Black patients undergo sacral neuromodulation for urinary incontinence less than White patients. There is less known about racial disparities in fecal incontinence.

To determine if racial disparities in fecal incontinence care exist, specifically sacral neuromodulation education.

This was a retrospective cohort study of adults treated for fecal incontinence from 2011 to 2021 at an academic health center.

Medical records were queried to collect clinical variables, including diagnostic tests ordered, treatments offered or discussed, and specialties treating the patients' fecal incontinence.

The two cohorts were patients who identified as non-Hispanic Black or non-Hispanic White.

The primary outcome was the percent of patients with documentation of discussion of sacral neuromodulation.

180 Black patients and 360 age-matched White patients were included. 21.7% of patients with fecal incontinence had documented counseling about sacral neuromodulation which was significantly less frequent in Black patients (12.8% vs 26.1%, p < 0.001). However, among only patients with this counseling documented, there was no difference based on race (17.4% vs 21.3%, p = 0.679). Black patients were also less likely to receive referrals for pelvic floor physical therapy (52.2% vs 72.2%, p < 0.001), anorectal manometry (41.1% vs 51.9%, p = 0.018), sphincter imaging (1.1% vs 5.3%, p = 0.018), and defecography (7.2% vs 16.1%, p = 0.004). Patients seen by Urogynecology, Colorectal Surgery, and/or Urology were more likely to be counseled about sacral neuromodulation (48.4% vs 2.8%, p < 0.001). On multivariate logistic regression, Black race (OR 0.45 95% CI 0.25-0.81), male sex (OR 3.15 95% CI 1.33-7.41), and not seeing a surgical specialist (OR 0.03 95% CI: 0.01-0.06) were associated with no sacral neuromodulation counseling.

Limitations include reliance on chart documentation for the primary outcome.

Racial differences in treatment of fecal incontinence exist between Black and White patients, including differences in counseling about sacral neuromodulation.

High-resolution colonic manometry is a research and diagnostic tool used to evaluate colonic motility. Used in health it helps us understand normal colonic motility and the colonic response to physiological stimuli such as meal, as well as chemical (laxatives) and mechanical (distension) stimuli. In pediatric and adult patients with suspected colonic disorders, it can help to understand the abnormal colonic motility associated with the condition.

High-resolution manometric catheters contain multiple closely spaced sensors that detect intraluminal pressure changes and contractile force, which can be interpreted as contractile activity. This activity forms several distinctive motor patterns that help in understanding normal colonic physiology and provide insights into the potential pathophysiology underlying colonic disorders such as constipation. After a PubMed search of colonic high-resolution manometry studies, this review provides an overview of the characterized motor patterns, when they occur, how they are initiated, their clinical relevance, and their role, if any, in guiding therapeutic interventions.

High-resolution colonic manometry has identified motor patterns that were missed or mislabeled by low-resolution recordings. How best to use this information to guide treatment remains to be determined.

Sacral neuromodulation (SNM) is an effective treatment for fecal incontinence (FI). Previous studies found that Black women undergo SNM for urinary incontinence less than White women, but there is less known about racial disparities for FI.

This study assessed differences in Black and White patients' FI treatment; SNM counseling was the primary outcome.

This was a retrospective cohort study of adult non-Hispanic Black and White patients who received FI treatment at an academic institution from 2011 to 2021. Medical records were queried for treatments, testing, and treating specialties for a 2:1 age-matched cohort of White:Black patients.

Four hundred forty-seven women were included: 149 Black women and 298 age-matched White women. A total of 24.4% (109) of patients had documented SNM counseling, significantly fewer in Black patients (14.8% vs 29.2%, P < 0.001). A total of 5.1% (23) of patients received SNM, less frequent in Black patients (2.7% vs 6.4%, P = 0.003). Among patients with SNM counseling, there was no difference between cohorts. Black patients were less likely to be referred for physical therapy (59.7% vs 77.2%, P < 0.001), sphincter imaging (0.7% vs 5.7%, P = 0.011), and defecography (8.1% vs 17.1%, P = 0.009). Different specialties managed the 2 cohorts. Black patients were less likely to see urogynecology and colorectal surgery (21.5% vs 34.6%, P = 0.004; 9.4% vs 15.4%, P = 0.077). Patients seen by these surgeons were more likely to discuss SNM (48.6% vs 8.5%, P < 0.001).

There were differences between Black and White patients' FI treatment, including counseling about SNM. Multidisciplinary work is needed to provide equitable education for this life-altering condition.

People with central neurological disease or injury have a much higher risk of both faecal incontinence (FI) and constipation than the general population. There is often a fine line between the two symptoms, with management intended to ameliorate one risking precipitating the other. Bowel problems are observed to be the cause of much anxiety and may reduce quality of life in these people. Current bowel management is largely empirical, with a limited research base. The review is relevant to individuals with any disease directly and chronically affecting the central nervous system (post-traumatic, degenerative, ischaemic or neoplastic), such as multiple sclerosis, spinal cord injury, cerebrovascular disease, Parkinson's disease and Alzheimer's disease. This is an update of a Cochrane Review first published in 2001 and subsequently updated in 2003, 2006 and 2014.

To assess the effects of conservative, physical and surgical interventions for managing FI and constipation in people with a neurological disease or injury affecting the central nervous system.

We searched the Cochrane Incontinence Specialised Register (searched 27 March 2023), which includes searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, ClinicalTrials.gov, WHO ICTRP as well as handsearching of journals and conference proceedings; and all reference lists of relevant articles.

We included randomised, quasi-randomised (where allocation is not strictly random), cross-over and cluster-randomised trials evaluating any type of conservative, physical or surgical intervention against placebo, usual care or no intervention for the management of FI and constipation in people with central neurological disease or injury.

At least two review authors independently assessed the risk of bias in eligible trials using Cochrane's 'Risk of bias' tool and independently extracted data from the included trials using a range of prespecified outcome measures. We produced summary of findings tables for our main outcome measures and assessed the certainty of the evidence using GRADE.

We included 25 studies with 1598 participants. The studies were generally at high risk of bias due to lack of blinding of participants and personnel to the intervention. Half of the included studies were also at high risk of bias in terms of selective reporting. Outcomes were often reported heterogeneously across studies, making it difficult to pool data. We did not find enough evidence to be able to analyse the effects of interventions on individual central neurological diseases. Additionally, very few studies reported on the primary outcomes of self-reported improvement in FI or constipation, or Neurogenic Bowel Dysfunction Score. Conservative interventions compared with usual care, no active treatment or placebo Thirteen studies assessed this comparison. The interventions included assessment-based nursing, holistic nursing, probiotics, psyllium, faecal microbiota transplantation, and a stepwise protocol of increasingly invasive evacuation methods. Conservative interventions may result in a large improvement in faecal incontinence (standardised mean difference (SMD) -1.85, 95% confidence interval (CI) -3.47 to -0.23; 3 studies; n = 410; low-certainty evidence). We interpreted SMD ≥ 0.80 as a large effect. It was not possible to pool all data from studies that assessed improvement in constipation, but the evidence suggested that conservative interventions may improve constipation symptoms (data not pooled; 8 studies; n = 612; low-certainty evidence). Conservative interventions may lead to a reduction in mean time taken on bowel care (data not pooled; 5 studies; n = 526; low-certainty evidence). The evidence is uncertain about the effects of conservative interventions on condition-specific quality of life and adverse events. Neurogenic Bowel Dysfunction Score was not reported. Physical therapy compared with usual care, no active treatment or placebo Twelve studies assessed this comparison. The interventions included massage therapy, standing, osteopathic manipulative treatment, electrical stimulation, transanal irrigation, and conventional physical therapy with visceral mobilisation. Physical therapies may make little to no difference to self-reported faecal continence assessed using the St Mark's Faecal Incontinence Score, where the minimally important difference is five, or the Cleveland Constipation Score (MD -2.60, 95% CI -4.91 to -0.29; 3 studies; n = 155; low-certainty evidence). Physical therapies may result in a moderate improvement in constipation symptoms (SMD -0.62, 95% CI -1.10 to -0.14; 9 studies; n = 431; low-certainty evidence). We interpreted SMD ≥ 0.5 as a moderate effect. However, physical therapies may make little to no difference in Neurogenic Bowel Dysfunction Score as the minimally important difference for this tool is 3 (MD -1.94, 95% CI -3.36 to -0.51; 7 studies; n = 358; low-certainty evidence). We are very uncertain about the effects of physical therapies on the time spent on bowel care, condition-specific quality of life and adverse effects (all very low-certainty evidence). Surgical interventions compared with usual care, no active treatment or placebo No studies were found for surgical interventions that met the inclusion criteria for this review.

There remains little research on this common and, for patients, very significant issue of bowel management. The available evidence is almost uniformly of low methodological quality. The clinical significance of some of the research findings presented here is difficult to interpret, not least because each intervention has only been addressed in individual trials, against control rather than compared against each other, and the interventions are very different from each other. Understanding whether there is a clinically-meaningful difference from the results of available trials is largely hampered by the lack of uniform outcome measures. This is due to an absence of core outcome sets, and development of these needs to be a research priority to allow studies to be compared directly. Some studies used validated constipation, incontinence or condition-specific measures; however, others used unvalidated analogue scales to report effectiveness. Some studies did not use any patient-reported outcomes and focused on physiological outcome measures, which is of relatively limited significance in terms of clinical implementation. There was evidence in favour of some conservative interventions, but these findings need to be confirmed by larger, well-designed controlled trials, which should include evaluation of the acceptability of the intervention to patients and the effect on their quality of life.

Electrical stimulation of the gut has been investigated in recent decades with a view to treating various gastro-intestinal motility disorders including, among others, gastric electrical stimulation to relieve nausea and vomiting associated with gastroparesis and sacral neuromodulation to treat fecal incontinence and/or constipation. Although their symptomatic efficacy has been ascertained by randomized controlled trials, their mechanisms of action are not fully understood.

This review summarizes the past year's literature on the mechanisms of action of gut electrical stimulation therapies, including their impact on the gut-brain axis.

Sacral nerve stimulation (SNS) is a minimally invasive surgical procedure used to treat refractory constipation in children. While its efficacy in improving symptoms has been studied, its effect on colonic motor function remains unclear. This case series explores SNS's impact on colonic motor function in pediatric patients with idiopathic constipation, using high-resolution colonic manometry (HRCM).

Four pediatric patients with chronic idiopathic constipation underwent SNS placement for intractable symptoms and were subsequently evaluated via HRCM. Clinical characteristics, comorbidities, treatment regimens, and outcomes were reviewed. HRCM was conducted during the SNS-off and SNS-on phases. The motility index (MI) was measured during the SNS-off (fasting and postprandial) and SNS-on phases.

Four pediatric patients aged 8 to 21 years met the inclusion criteria. In three patients, SNS-induced high-amplitude propagating contractions (HAPCs) were noted, and in one patient, low-amplitude propagating contractions (LAPCs) were noted. In one patient, propagating contractions were induced only when SNS was turned on. MI changes with SNS-on were variable among different patients with an increase in MI in two patients after turning SNS on and a decrease in the other two compared with baseline. Adverse effects following SNS placement remained minimal across all cases.

This case series is the first to report SNS effects on colonic motility evaluated by HRCM in pediatrics. We demonstrate that propagating colonic contractions are promptly induced when SNS is turned on. Although the initial effects of SNS on colonic motility were observable, additional investigation is necessary to comprehend the fundamental mechanisms and long-term effectiveness of SNS in pediatric patients.

Abnormal cyclic motor pattern (CMP) activity is implicated in colonic dysfunction, but the only tool to evaluate CMP activity, high-resolution colonic manometry (HRCM), remains expensive and not widely accessible. This study aimed to validate body surface colonic mapping (BSCM) through direct correlation with HRCM. Synchronous meal-test recordings were performed in asymptomatic participants with intact colons. A signal processing method for BSCM was developed to detect CMPs. Quantitative temporal analysis was performed comparing the meal responses and motility indices (MI). Spatial heat maps were also compared. Post-study questionnaires evaluated participants' preference and comfort/distress experienced from either test. 11 participants were recruited and 7 had successful synchronous recordings (5 females/2 males; median age: 50 years [range 38-63]). The best-correlating MI temporal analyses achieved a high degree of agreement (median Pearson correlation coefficient (Rp) value: 0.69; range 0.47-0.77). HRCM and BSCM meal response start and end times (Rp = 0.998 and 0.83; both p < 0.05) and durations (Rp = 0.85; p = 0.03) were similar. Heat maps demonstrated good spatial agreement. BSCM is the first non-invasive method to be validated by demonstrating a direct spatio-temporal correlation to manometry in evaluating colonic motility.

A rhythmic expression of clock genes occurs within the cells of multiple organs and tissues throughout the body, termed "peripheral clocks." Peripheral clocks are subject to entrainment by a multitude of factors, many of which are directly or indirectly controlled by the light-entrainable clock located in the suprachiasmatic nucleus of the hypothalamus. Peripheral clocks occur in the gastrointestinal tract, notably the epithelia whose functions include regulation of absorption, permeability, and secretion of hormones; and in the myenteric plexus, which is the intrinsic neural network principally responsible for the coordination of muscular activity in the gut. This review focuses on the physiological circadian variation of major colonic functions and their entraining mechanisms, including colonic motility, absorption, hormone secretion, permeability, and pain signalling. Pathophysiological states such as irritable bowel syndrome and ulcerative colitis and their interactions with circadian rhythmicity are also described. Finally, the classic circadian hormone melatonin is discussed, which is expressed in the gut in greater quantities than the pineal gland, and whose exogenous use has been of therapeutic interest in treating colonic pathophysiological states, including those exacerbated by chronic circadian disruption.

Patients with irritable bowel syndrome (IBS) have recurrent lower abdominal pain, associated with altered bowel habit (diarrhea and/or constipation). As bowel habit is altered, abnormalities in colonic motility are likely to contribute; however, characterization of colonic motor patterns in patients with IBS remains poor. Utilizing fiber-optic manometry, we aimed to characterize distal colonic postprandial colon motility in diarrhea-predominant IBS. After an overnight fast, a 72-sensor (spaced at 1-cm intervals) manometry catheter was colonoscopically placed to the proximal colon, in 13 patients with IBS-D and 12 healthy adults. Recordings were taken for 2 h pre and post a 700 kcal meal. Data were analyzed with our two developed automated techniques. In both healthy adults and patients with IBS-D, the dominant frequencies of pressure waves throughout the colon are between 2 and 4 cycles per minute (cpm) and the power of these frequencies increased significantly after a meal. Although these pressure waves formed propagating contractions in both groups, the postprandial propagating contraction increase was significantly smaller in patients compared with healthy adults. In healthy adults during the meal period, retrograde propagation between 2 and 8 cpm was significantly greater than antegrade propagation at the same frequencies. This difference was not observed in IBS-D. Patients with IBS-D show reduced prevalence of the retrograde cyclic motor pattern postprandially compared with the marked prevalence in healthy adults. We hypothesize that this reduction may allow premature rectal filling, leading to postprandial urgency and diarrhea.NEW & NOTEWORTHY Compared with healthy adults this study has shown a significant reduction in the prevalence of the postprandial retrograde cyclic motor pattern in the distal colon of patients with diarrhea-predominant irritable bowel syndrome. We hypothesize that this altered motility may allow for premature rectal filling which contributes to the postprandial urgency and diarrhea experienced by these patients.

Children with anorectal malformations may experience constipation and fecal incontinence following repair. The contribution of altered anorectal function to these persistent symptoms is relatively intuitive; however, colonic motility in this cohort is less well understood. Manometry may be used to directly assess colonic motility.

The purpose of this systematic review was to synthesize the available evidence regarding post-operative colonic motility in children with anorectal malformations and evaluate the reported equipment and protocols used to perform colonic manometry in this cohort. This systematic review was conducted in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We conducted a systematic review of four databases: Embase, MEDLINE, PubMed, and the Cochrane Library (1^st January 1985-22^nd July 2021). Studies reporting colonic manometry performed in children following anorectal malformation repair were assessed for eligibility. Data were extracted independently by two authors. Four studies were eligible for inclusion. Of the combined total cohort of 151 children, post-operative colonic manometry was conducted in 35. Insufficient reporting of medical characteristics, bowel function, and manometric outcomes restricted comparison between studies, and limited clinical applicability. No results from high-resolution colonic manometry were identified. Despite the prevalence of post-operative bowel dysfunction in children with repaired anorectal malformations, this systematic review highlighted the markedly limited evidence regarding post-operative colonic motility. This cohort may benefit from assessment with high-resolution techniques; however, future work must emphasize adherence to standardized manometry protocols, and include robust reporting of surgical characteristics, bowel function, and manometric outcomes.

The rectosigmoid brake, characterised by retrograde cyclic motor patterns on high-resolution colonic manometry, has been postulated as a contributor to the maintenance of bowel continence. Sacral neuromodulation (SNM) is an effective therapy for faecal incontinence, but its mechanism of action is unclear. This study aims to investigate the colonic motility patterns in the distal colon of patients with faecal incontinence, and how these are modulated by SNM.

A high-resolution fibreoptic colonic manometry catheter, containing 36 sensors spaced at 1-cm intervals, was positioned in patients with faecal incontinence undergoing stage 1 SNM. One hour of pre- and post meal recordings were obtained followed by pre- and post meal recordings with suprasensory SNM. A 700-kcal meal was given. Data were analysed to identify propagating contractions.

Fifteen patients with faecal incontinence were analysed. Patients had an abnormal meal response (fewer retrograde propagating contractions compared to controls; p = 0.027) and failed to show a post meal increase in propagating contractions (mean 17 ± 6/h premeal vs. 22 ± 9/h post meal, p = 0.438). Compared to baseline, SNM significantly increased the number of retrograde propagating contractions in the distal colon (8 ± 3/h premeal vs. 14 ± 3/h premeal with SNM, p = 0.028). Consuming a meal did not further increase the number of propagating contractions beyond the baseline upregulating effect of SNM.

The rectosigmoid brake was suppressed in this cohort of patients with faecal incontinence. SNM may exert a therapeutic effect by modulating this rectosigmoid brake.

In the human large bowel, sacral parasympathetic nerves arise from S2 to S4, project to the pelvic plexus ("hypogastric plexus") and have post-ganglionic axons entering the large bowel near the rectosigmoid junction. They then run long distances orally or aborally within the bowel wall forming "ascending nerves" or "shunt fascicles" running in the plane of the myenteric plexus. They form bundles of nerve fibres that can be distinguished from the myenteric plexus by their straight orientation, tendency not to merge with myenteric ganglia and greater width.

To identify reliable marker(s) to distinguish these bundles of ascending nerves from other extrinsic and intrinsic nerves in human colon.

Human colonic segments were obtained with informed consent, from adult patients undergoing elective surgery (n = 21). Multi-layer immunohistochemical labelling with neurofilament-H (NF200), myelin basic protein (MBP), von Willebrand factor (vWF), and glucose transporter 1 (GLUT1), and rapid anterograde tracing with biotinamide, were used to compare ascending nerves and lumbar colonic nerves.

The rectosigmoid and rectal specimens had 6-11 ascending nerves spaced around their circumference. Distal colon specimens typically had 1-3 ascending nerves, with one located near the mesenteric taenia coli. No ascending nerves were observed in ascending colon specimens. GLUT1 antisera labelled both sympathetic lumbar colonic nerves and ascending nerves in the gut wall. Lumbar colonic nerves joined the myenteric plexus and quickly lost GLUT1 labelling, whereas GLUT1 staining labelled parasympathetic ascending nerves over many centimetres.

Ascending nerves can be distinguished in the colorectum of humans using GLUT1 labelling combined with NF200.

Constipation in children is a major health issue around the world, with a global prevalence of 9.5%. They present to clinicians with a myriad of clinical signs. The Rome IV symptom-based criteria are used to diagnose functional constipation. Functional constipation is also a huge financial burden for healthcare system and has a detrimental impact on health-related quality of life of children. There are various risk factors identified globally, including centrally connected factors such as child abuse, emotional and behavioral issues, and psychological stress. Constipation is also precipitated by a low-fiber diet, physical inactivity, and an altered intestinal microbiome. The main pathophysiological mechanism is stool withholding, while altered rectal function, anal sphincter, pelvic floor, and colonic dysfunction also play important roles. Clinical evaluation is critical in making a diagnosis, and most investigations are only required in refractory patients. In the treatment of childhood constipation, both nonpharmacological (education and de-mystification, dietary changes, toilet training, behavioral interventions, biofeedback, and pelvic floor physiotherapy), and pharmacological (osmotic and stimulant laxatives and novel drugs like prucalopride and lubiprostone) interventions are used. For children with refractory constipation, transanal irrigation, botulinum toxin, neuromodulation, and surgical treatments are reserved. While frequent use of probiotics is still in the experimental stage, healthy dietary habits, living a healthy lifestyle and limiting exposure to stressful events, are all beneficial preventive measures.

Fecal incontinence (FI) is defined as the involuntary loss or passage of solid or liquid stool in patients. FI is a common and debilitating condition in men and women. The incidence increases with age and also often goes unreported to health care providers. It is crucial that providers ask at-risk patients about possible symptoms. Evaluation and management is tailored to specific symptoms and characteristics of the incontinence. If conservative methods fail to improve symptoms, then other surgical options are considered, such as sacral nerve stimulation and anal sphincter augmentation. This review provides an update on current and future therapies.

The colonic motor patterns associated with gas transit are poorly understood. This study describes the application of high-resolution impedance manometry (HRiM) in the human colon in vivo to characterize distal colonic motility and gas transit; (a) after a meal and (b) after intraluminal gas insufflation into the sigmoid colon.

HRiM recordings were performed in 19 healthy volunteers, with sensors positioned from the distal descending colon to the proximal rectum. Protocol 1 (n = 10) compared pressure and impedance prior to and after a meal. Protocol 2 (n = 9) compared pressure and impedance before and after gas insufflation into the sigmoid colon (60 mL total volume).

Both the meal and gas insufflation resulted in an increase in the prevalence of the 2-8/minute "cyclic motor pattern" (meal: (t(9) = -6.42, P<0.001); gas insufflation (t(8) = -3.13, P = 0.01)), and an increase in the number of antegrade and retrograde propagating impedance events (meal: Z = -2.80, P = 0.005; gas insufflation Z = -2.67, P = 0.008). Propagating impedance events temporally preceded antegrade and retrograde propagating contractions, representing a column of luminal gas being displaced ahead of a propagating contraction. Three participants reported an urge to pass flatus and/or flatus during the studies.

Initiation of the 2-8/minute cyclic motor pattern in the distal colon occurs both following a meal and/or as a localized sensorimotor response to gas. The near-absence of a flatal urge and the temporal association between propagating contractions and gas transit supports the hypothesis that the 2-8/minute cyclic motor pattern acts as a physiological "brake" modulating rectal filling.

The aim of this study was to determine whether stimulation of sacral spinal nerve roots can induce defecation in cats. In anesthetized cats, bipolar hook electrodes were placed on the S1-S3 dorsal and/or ventral roots. Stimulus pulses (1-50 Hz, 0.2 ms) were applied to an individual S1-S3 root to induce proximal/distal colon contractions and defecation. Balloon catheters were inserted into the proximal and distal colon to measure contraction pressure. Glass marbles were inserted into the rectum to demonstrate defecation by videotaping the elimination of marbles. Stimulation of the S2 ventral root at 7 Hz induced significantly (P < 0.05) larger contractions (32 ± 9 cmH₂O) in both proximal and distal colon than stimulation of the S1 or S3 ventral root. Intermittent (5 times) stimulation (1 min on and 1 min off) of both dorsal and ventral S2 roots at 7 Hz produced reproducible colon contractions without fatigue, whereas continuous stimulation of 5-min duration caused significant fatigue in colon contractions. Stimulation (7 Hz) of both dorsal and ventral S2 roots together successfully induced defecation that eliminated 1 or 2 marbles from the rectum. This study indicates the possibility to develop a novel neuromodulation device to restore defecation function after spinal cord injury using a minimally invasive surgical approach to insert a lead electrode via the sacral foramen to stimulate a sacral spinal root.NEW & NOTEWORTHY This study in cats determined the optimal stimulation parameters and the spinal segment for sacral spinal root stimulation to induce colon contraction. The results have significant implications for design of a novel neuromodulation device to restore defecation function after spinal cord injury (SCI) and for optimizing sacral neuromodulation parameters to treat non-SCI people with chronic constipation.

Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.

The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

Cyclic motor patterns (CMP) are the predominant motor pattern in the distal colon, and are important in both health and disease. Their origin, mechanism and relation to bioelectrical slow-waves remain incompletely understood. During abdominal surgery, an increase in the CMP occurs in the distal colon. This study aimed to evaluate the feasibility of detecting propagating slow waves and spike waves in the distal human colon through intraoperative, high-resolution (HR), serosal electrical mapping.

HR electrical recordings were obtained from the distal colon using validated flexible PCB arrays (6 × 16 electrodes; 4 mm inter-electrode spacing; 2.4 cm2, 0.3 mm diameter) for up to 15 min. Passive unipolar signals were obtained and analysed.

Eleven patients (33-71 years; 6 females) undergoing colorectal surgery under general anaesthesia (4 with epidurals) were recruited. After artefact removal and comprehensive manual and automated analytics, events consistent with regular propagating activity between 2 and 6 cpm were not identified in any patient. Intermittent clusters of spike-like activities lasting 10-180 s with frequencies of each cluster ranging between 24 and 42 cpm, and an average amplitude of 0.54 ± 0.37 mV were recorded.

Intraoperative colonic serosal mapping in humans is feasible, but unlike in the stomach and small bowel, revealed no regular propagating electrical activity. Although sporadic, synchronous spike-wave events were identifiable. Alternative techniques are required to characterise the mechanisms underlying the hyperactive CMP observed in the intra- and post-operative period.

The aim of this study was to assess the feasibility of detecting propagating electrical activity that may correlate to the cyclic motor pattern in the distal human colon through intraoperative, high-resolution, serosal electrical mapping. High-resolution electrical mapping of the human colon revealed no regular propagating activity, but does reveal sporadic spike-wave events. These findings indicate that further research into appropriate techniques is required to identify the mechanism of hyperactive cyclic motor pattern observed in the intra- and post-operative period in humans.

Fecal incontinence is a highly prevalent and debilitating condition that negatively impacts quality of life. The etiology is often multifactorial and treatment can be hindered by lack of understanding of its mechanisms and available treatment options. This article reviews the evidence-based update for the management of fecal incontinence.

Scleroderma is a chronic autoimmune disorder involving multiple organs and very commonly the gastrointestinal (GI) system; nevertheless, data on the involvement of the anal sphincter and consequent faecal incontinence (FI) are inadequate. FI in scleroderma was first reported in 1994 by Engel and colleagues, but its impact of added health care costs and declining quality of life (QoL) is poorly determined. Up to 40% of patients with GI involvement complain of FI, however, the quality of data available is poor owing to majority of the studies being retrospective and case reports or series of small study size. A direct involvement of internal anal sphincter muscularis propria has been demonstrated on anorectal ultrasound imaging suggesting a thin, atrophic or scarred internal sphincter. Treatment guidelines for incontinence in scleroderma are mainly symptomatic, with radical surgeries burdened by poor outcomes. Sacral neuromodulation is being used with good outcomes in a subgroup of patients, but larger, controlled studies are required to assess its efficacy on symptoms and prognosis.

Patients frequently suffer from low anterior resection syndrome (LARS) after distal colorectal resection. The pathophysiology of LARS has not been clearly elucidated. We hypothesized that rectosigmoid resection could impair motility patterns in the distal colon, such as the rectosigmoid brake, which contribute to control of stool form and frequency.

High-resolution colonic manometry was performed in patients who had previously undergone distal colorectal resection (mean 6.8 years after resection) and non-operative controls before and after a standardized meal. Symptoms were assessed using the LARS score. Propagating contractions were compared between patients with and without LARS, and controls.

Data were analysed from 23 patients (11 no-LARS; 12 LARS) and nine controls. All groups demonstrated a significant meal response. LARS patients had fewer post-prandial antegrade propagating contractions than controls (P = 0.028), and fewer retrograde propagating contractions both pre- (P = 0.005) and post-prandially (P = 0.004). Post-prandially, the LARS group had a significantly lower percentage of propagating contractions that met the criteria for the cyclic motor pattern compared to the control group (26% vs. 58%; P = 0.009). There were significant differences in antegrade and retrograde amplitude (P = 0.049; P = 0.018) and distance of propagation (P = 0.003; P = 0.002) post-prandially between LARS patients and controls.

Rectosigmoid resection alters the meal response following anterior resection, including impairment of the rectosigmoid brake cyclic motor pattern. These findings help to quantify the impaired functional motility after rectosigmoid resection and offer new insights into the mechanisms of LARS.

Colonic high-resolution manometry (cHRM) is an emerging clinical tool for defining colonic function in health and disease. Current analysis methods are conducted manually, thus being inefficient and open to interpretation bias.

The main objective of the study was to build an automated system to identify propagating contractions and compare the performance to manual marking analysis.

cHRM recordings were performed on 5 healthy subjects, 3 subjects with diarrhea-predominant irritable bowel syndrome, and 3 subjects with slow transit constipation. Two experts manually identified propagating contractions, from five randomly selected 10-min segments from each of the 11 subjects (72 channels per dataset, total duration 550 min). An automated signal processing and detection platform was developed to compare its effectiveness to manually identified propagating contractions. In the algorithm, individual pressure events over a threshold were identified and were then grouped into a propagating contraction. The detection platform allowed user-selectable thresholds, and a range of pressure thresholds was evaluated (2 to 20 mmHg).

The automated system was found to be reliable and accurate for analyzing cHRM with a threshold of 15 mmHg, resulting in a positive predictive value of 75%. For 5-h cHRM recordings, the automated method takes 22 ± 2 s for analysis, while manual identification would take many hours.

An automated framework was developed to filter, detect, quantify, and visualize propagating contractions in cHRM recordings in an efficient manner that is reliable and consistent.

Diagnostic investigations for fecal incontinence (FI) assess the structure and sensorimotor function of the anorectum. Investigations include anorectal manometry, anorectal sensory testing, pudendal nerve terminal motor latencies (PNTML), and endoanal sonography. The severity of FI and results of investigations are often discordant and the rate of symptom resolution following treatment remains <40%. High-resolution anorectal manometry (HRAM) and three-dimensional endoanal ultrasound (3D-US) have been introduced during the last decade. This study aims to assess the strength of relationships between contemporary investigation results and FI severity.

Adults presenting for investigation of FI were assessed using the St Mark's FI severity score (SMIS), HRAM, anorectal sensory testing, PNTML, and 3D-US.

246 patients were included. There were significant relationships between the SMIS and HRAM (resting pressure r_s = -0.23, 95% CI = (-0.34, -0.11), P < .001; squeeze pressure (r_s  = -0.26, 95% CI = (-0.37, -0.14), P < .001) and 3D-US (anterior EAS length r_s = -0.22, 95% CI = (-0.34, -0.09), P = .001). The relationships between SMIS and HRAM had a greater effect size in those with urge-predominant symptoms (resting pressure: r_s = -0.40, 95% CI = (-0.57, -0.20), P < .001, squeeze pressure: r_s = -0.34, 95% CI = (-0.52, -0.12), P = .003). Overall, the variance in SMIS accounted for by anorectal investigations was 8.6% (R² = 0.098, adjusted R² = 0.086, P < .001).

Anorectal investigations are not strong predictors of FI severity. These findings may reflect the multifactorial, heterogeneous pathophysiology of FI, the limitations of the SMIS and anorectal investigations, and contributing factors extrinsic to the anorectum.

Fecal incontinence is a disabling condition affecting up to 20% of women.

We investigated fecal incontinence assessment in both inflammatory bowel disease and non-inflammatory bowel disease patients to propose a diagnostic approach for inflammatory bowel disease trials.

We searched on Pubmed, Embase and Cochrane Library for all studies on adult inflammatory bowel disease and non-inflammatory bowel disease patients reporting data on fecal incontinence assessment from January 2009 to December 2019.

In total, 328 studies were included; 306 studies enrolled non-inflammatory bowel disease patients and 22 studies enrolled inflammatory bowel disease patients. In non-inflammatory bowel disease trials the most used tools were the Wexner score, fecal incontinence quality of life questionnaire, Vaizey score and fecal incontinence severity index (in 187, 91, 62 and 33 studies). Anal manometry was adopted in 41.2% and endoanal ultrasonography in 34.0% of the studies. In 142 studies (46.4%) fecal incontinence evaluation was performed with a single instrument, while in 64 (20.9%) and 100 (32.7%) studies two or more instruments were used. In inflammatory bowel disease studies the Wexner score, Vaizey score and inflammatory bowel disease quality of life questionnaire were the most commonly adopted tools (in five (22.7%), five (22.7%) and four (18.2%) studies). Anal manometry and endoanal ultrasonography were performed in 45.4% and 18.2% of the studies.

Based on prior validation and experience, we propose to use the Wexner score as the first step for fecal incontinence assessment in inflammatory bowel disease trials. Anal manometry and/or endoanal ultrasonography should be taken into account in the case of positive questionnaires.

To compare antegrade continence enema (ACE) treatment and sacral nerve stimulation (SNS) in children with intractable functional constipation (FC) and fecal incontinence (FI).

We performed a retrospective review of children 6-18 years old with FC and FI treated with either ACE or SNS at our institution. We recorded symptoms at baseline, 6 months, 12 months, 24 months, and their most recent visit after starting treatment. We compared improvement in FI, bowel movement (BM) frequency, abdominal pain, laxative use, and complications. Patients were contacted to evaluate perceived benefit using the Glasgow Children's Benefit Inventory.

We included 23 patients treated with ACE (52% female, median age 10 years) and 19 patients treated with SNS (74% female, median age 10 years). Improvement in FI was greater with SNS than ACE at 12 months (92.9% vs 57.1%, P = .03) and 24 months (100% vs 57.1%, P = .02). Improvement in BM frequency was greater with ACE, and children were more likely to discontinue laxatives at all follow-up time points (all P < .05). Improvement in abdominal pain was greater with ACE at the most recent visit (P < .05). Rate of complications requiring surgery was similar between groups (26.3% vs 21.7%). Benefit was reported in 83.3% and 100% of ACE and SNS groups, respectively (NS).

Although both ACE and SNS can lead to durable improvement in children with FC and FI, SNS appears more effective for FI and ACE more effective in improving BM frequency and abdominal pain and in discontinuation of laxatives.

In a recent study of sacral nerve stimulation (SNS) for colonic inflammation, a possible spinal-vagal pathway was implicated. The aim of this study was to provide evidence for such a pathway by investigating the effects of SNS on dysmotility of the stomach and duodenum that are not directly innervated by the sacral efferents.

Twenty-seven rats were chronically implanted with wire electrodes for SNS and gastrointestinal slow waves. SNS was performed in several acute sessions to investigate its effects on gastric/duodenal slow waves and emptying/transit impaired by glucagon and rectal distention (RD).

(a) SNS increased the percentage of normal gastric slow waves impaired by glucagon (from 53.9% to 77.0%, P < .0001) and RD (from 64% to 78%, P = .037). This improvement was abolished by atropine. (b) Similar effects were observed with SNS on duodenal slow waves, which was also blocked by atropine. (c) SNS normalized delayed gastric emptying induced by glucagon (control: 61.3%, glucagon: 44.3%, glucagon + SNS: 65.8%) and RD (control: 61.3%, RD: 46.7%, RD + SNS: 64.3%). It also normalized small intestinal transit delayed by RD (P = .001, RD + SNS vs RD; P = .9, RD + SNS vs control). (4) Both glucagon and RD induced an increase in the sympathovagal ratio (P = .007, glucagon vs baseline; P < .001, RD vs baseline) and SNS decreased the ratio (P = .006, glucagon + SNS vs glucagon; P = .04, RD + SNS vs RD).

Neuromodulation of the sacral nerve improves gastric and small intestinal pacemaking activity and transit impaired by glucagon and RD by normalizing the sympathovagal balance via a retrograde neural pathway from the sacral nerve to vagal efferents.

High-resolution colonic manometry is an emerging technique that has provided new insights into the pathophysiology of functional colorectal diseases. Prior studies have been limited by bulky, non-ambulatory acquisition systems, which have prevented mobilization during prolonged recordings.

A novel ambulatory acquisition system for fiber-optic high-resolution colonic manometry was developed. Benchtop validation against a standard non-ambulatory system was performed using standardized calibration metrics. Clinical feasibility studies were conducted in three patients undergoing right hemicolectomy.

Pressure profiles obtained from benchtop testing were near-identical using the ambulatory and the non-ambulatory systems. Clinical studies successfully demonstrated ambulatory data capture with patients freely mobilizing postoperatively during continuous recordings of >60 hours. The occurrence (P = .56), amplitude (P = .65), velocity (P = .10), and extent (P = .12) of colonic motor patterns were similar to those obtained in non-ambulatory studies.

A novel ambulatory system for high-resolution colonic manometry has been developed and validated. This technique will facilitate prolonged ambulatory recordings of colonic motor activity, assisting with investigations into the role of colonic motility in disease states.

Introduction: In recent decades, medical devices (MDs) have increasingly become an integral part of patient care. However, when it comes to designing and appraising economic models, researchers typically follow pharmaceutical templates (e.g. CHEERS) to assess their economic viability. This study evaluates the generalizability of four device-specific criteria, as recommended by the recent MedtechHTA project, of learning curve, incremental innovation, dynamic pricing, and organizational impact with a broader group of MDs including diagnostics and implantables. The purpose was to determine the applicability of these criteria to a broader range of MDs.Areas Covered: We determined the extent to which these criteria could be applied to each device type and attempted to identify common themes. We performed a literature search using PubMed and Google of a range of devices to understand the clinical significance, operation, and economic viability.Expert Opinion: Our findings suggest that the four characteristics are not applicable to all device types. Prior evaluation of a device's intrinsic properties (such as longevity and device location) and its FDA risk classification could help to indicate the applicability of the criteria. Documenting this process when assessing the additional four criteria on the CHEERS checklist would improve the transparency of future economic evaluations.

Although sacral nerve stimulation (SNS) has been applied for treating constipation, its parameters were adopted from SNS for fecal incontinence, its effects are limited, and mechanisms are largely unknown. We investigated the effects and mechanism of SNS with appropriate parameters on constipation in rats treated with loperamide. First, using rectal compliance as an outcome measure, an experiment was performed to derive effective SNS parameters. Then, a 7-day SNS was performed in rats with constipation induced by loperamide. Autonomic functions were assessed by spectral analysis of heart rate variability (HRV) derived from an electrocardiogram. Serum levels of pancreatic polypeptide (PP), norepinephrine (NE), and acetylcholine (ACh) in colon were assessed. 1) Acute SNS at 5 Hz, 100 µs was found effective in enhancing rectal compliance and accelerating distal colon transit (P < 0.05 vs. sham SNS). 2) The 7-day SNS normalized loperamide-induced constipation, assessed by the number, weight, and water content of fecal pellets, and accelerated the distal colon transit (29.4 ± 3.7 min with sham SNS vs. 16.4 ± 5.3 min with SNS but not gastric emptying or intestinal transit. 3) SNS significantly increased vagal activity (P = 0.035) and decreased sympathetic activity (P = 0.012), assessed by spectral analysis of HRV as well as by the serum PP. 4) SNS increased ACh in the colon tissue; atropine blocked the accelerative effect of SNS on distal colon transit. We concluded that SNS with appropriate parameters improves constipation induced by loperamide by accelerating distal colon motility, mediated via the autonomic-cholinergic function.NEW & NOTEWORTHY Although sacral nerve stimulation (SNS) has been applied for treating constipation, its parameters were adopted from SNS for fecal incontinence, effects are limited, and mechanisms are largely unknown. This paper shows that SNS with appropriate parameters improves constipation induced by loperamide by accelerating distal colon motility mediated via the autonomic-cholinergic function.

Alterations in colonic motility are implicated in the pathophysiology of bowel disorders, but high-resolution manometry of human colonic motor function has revealed that our knowledge of normal motor patterns is limited. Furthermore, various terminologies and definitions have been used to describe colonic motor patterns in children, adults and animals. An example is the distinction between the high-amplitude propagating contractions in humans and giant contractions in animals. Harmonized terminology and definitions are required that are applicable to the study of colonic motility performed by basic scientists and clinicians, as well as adult and paediatric gastroenterologists. As clinical studies increasingly require adequate animal models to develop and test new therapies, there is a need for rational use of terminology to describe those motor patterns that are equivalent between animals and humans. This Consensus Statement provides the first harmonized interpretation of commonly used terminology to describe colonic motor function and delineates possible similarities between motor patterns observed in animal models and humans in vitro (ex vivo) and in vivo. The consolidated terminology can be an impetus for new research that will considerably improve our understanding of colonic motor function and will facilitate the development and testing of new therapies for colonic motility disorders.

Anorectal dysfunction is the focus of diagnostic investigations for faecal incontinence. However, severity of incontinence and anorectal investigation results can be discordant. The aim of this study was to define the relationships between anorectal investigation results and incontinence severity to determine which measures, if any, were predictive of incontinence severity.

Patients presenting for investigation of faecal incontinence completed a symptom questionnaire, anorectal manometry, rectal sensation, pudendal nerve terminal motor latency, and endoanal ultrasound. Bivariate analyses were conducted between the Jorge-Wexner score and investigation results. Subgroup analyses were performed for gender and symptom subtypes (urge, passive, mixed). A multiple regression analysis was performed.

Five hundred and thirty-eight patients were included. There were weak correlations between the Jorge-Wexner score and maximal squeeze pressure [r = - 0.24, 95%CI(- 0.31, - 0.16), p < 0.001], and resting pressure [r = - 0.18, (95%CI(- 0.26, - 0.10), p < 0.001]. In men only, there were significant associations between the Jorge-Wexner score and endoanal sonography [IAS defects: t(113) = - 2.26, p = 0.03, d = 0.58, 95%CI(- 4.38, - 0.29)] and rectal sensation (MTV: r_s = - 0.24, 95%CI(- 0.41, - 0.06), p = 0.01). No substantial differences were observed in the urge/passive/mixed subgroup analyses. Multiple regression analysis included three variables: age (β = 0.02, p = 0.17), maximal resting pressure (β = - 0.01, p = 0.28), and maximal squeeze pressure (β = - 0.01, p < 0.01). The variance in the Jorge-Wexner score accounted for by this model was < 10%, (R² = 0.07, p = < 0.01, adjusted R² = 0.06).

Anorectal investigations cannot predict the severity of faecal incontinence. This may be due to limitations of diagnostic modalities, the heterogeneity of anorectal dysfunction in these patients, or contributing factors which are extrinsic to the anorectum.

The aim of the present study was to evaluate percutaneous tibial nerve stimulation (PTNS) for treatment resistant chronic anal fissure.

Consecutive patients with chronic anal fissure were treated with neuromodulation via the posterior tibial nerve between October 2013 and January 2014. Patients had PTNS for 30 min on 10 consecutive days. All patients had failed conventional medical treatment. The visual analogue scale (VAS) score, St. Marks score, Wexner's constipation score, Brief Pain Inventory (BPI-SF), bleeding and mucosal healing were evaluated before treatment, at termination, after 3 months, and then yearly for 3 years.

Ten patients (4 males and 6 females; mean age 49.8 years) were identified but only 9 were evaluated as one patient's fissure healed before PTNS was started. At 3-year follow-up, fissures had remained completely healed in 5 out of 9 patients. All patients stopped bleeding and were almost completely pain-free at 3 years (VAS p = 0.010) and pain relief improved from 50% at completion to 90% at 3 years. The patients' Wexner constipation scores improved significantly (p = 0.007).

In this small series, PTNS enhanced healing of chronic anal fissure and reduced pain and bleeding with an associated improvement in bowel function.

Many patients with fecal incontinence report coexisting constipation. This subset of patients has not been well characterized or understood.

The purpose of this study was to report the frequency of fecal incontinence with concurrent constipation and to compare quality-of-life outcomes of patients with fecal incontinence with and without constipation.

This was a prospective cohort study. Survey data, including Fecal Incontinence Severity Index, Constipation Severity Instrument, Fecal Incontinence Quality of Life survey (categorized as lifestyle, coping, depression, and embarrassment), Pelvic Organ Prolapse Inventory and Urinary Distress Inventory surveys, and anorectal physiology testing were obtained.

The study was conducted as a single-institution study from January 2007 to January 2017.

Study patients had fecal incontinence presented to a tertiary pelvic floor center.

Quality-of-life survey findings were measured.

A total of 946 patients with fecal incontinence were identified, and 656 (69.3%) had coexisting constipation. Patients with fecal incontinence with constipation were less likely to report a history of pregnancy (89.2% vs 91.4%; p = 0.001) or complicated delivery, such as requiring instrumentation (9.1% vs 18.1%; p = 0.005), when compared with patients with isolated fecal incontinence. Patients with fecal incontinence with constipation had higher rates of coexisting pelvic organ prolapse (Pelvic Organ Prolapse Inventory: 18.4 vs 8.2; p < 0.01), higher rates of urinary incontinence (Urinary Distress Inventory: 30.2 vs 23.4; p = 0.01), and higher pressure findings on manometry; intussusception on defecography was common. Patients with fecal incontinence with concurrent constipation had less severe incontinence scores at presentation (21.0 vs 23.8; p < 0.001) and yet lower overall health satisfaction (28.9% vs 42.5%; p < 0.001). Quality-of-life scores declined as constipation severity increased for lifestyle, coping, depression, and embarrassment.

This was a single-institution study, and surgeon preference could bias population and anorectal physiology testing.

Patients with fecal incontinence with concurrent constipation represent a different disease phenotype and have different clinical and anorectal physiology test findings and worse overall quality of life. Treatment of these patients requires careful consideration of prolapse pathology with coordinated treatment of coexisting disorders. See Video Abstract at http://links.lww.com/DCR/A783.

In recent years, high-resolution manometry has been used in an attempt to gain a greater insight into the physiology/pathophysiology of colonic contractile activity in healthy adults and patients with colonic motility disorders. New colonic motor patterns have been identified and characterized, however, the clinical significance of these findings remains undetermined.

This review will assess the current literature on colonic high-resolution manometry and determine if this procedure has advanced our understanding of colonic motility. The limitations, future directions, and the potential of this technique to assess the effects of treatment upon colonic motor patterns will also be discussed.

Sphincter preserving surgery for the treatment of rectal cancer is very often feasible, avoiding a permanent colostomy. It is well recognized that a large proportion of patients will experience altered bowel habit following low anterior resection (LAR). Faecal incontinence is a common symptom associated with LAR syndrome. The aim of this study is to evaluate the long-term improvement in continence and quality of life (QoL) in LAR patients treated with sacral nerve modulation.

Patients with ongoing faecal incontinence for >1 year after reversal of diverting ileostomy post ultra-LAR were selected for the study. Eligible patients underwent sacral nerve modulator implantation as a two-stage procedure. Bowel diaries and the Cleveland Clinic Faecal Incontinence Score were used to measure faecal incontinence and QoL.

Twelve patients underwent permanent implantation of a sacral nerve stimulator. Median follow-up was 34 months (interquartile range (IQR) 20.25-62.5 months). The median improvement in faecal incontinence was 90% (IQR 76.25-98.75%) and the median improvement in patient QoL was 80% (IQR 71.25-93.75%). Patients who had previously been treated with biofeedback showed a median improvement in incontinence of 75% compared to 90% which was found in patients who had not had prior biofeedback treatment. The mean percentage improvement in patients with an internal anal sphincter defect was 80% compared to 90% seen in patients with an intact sphincter.

The results of this study suggest that sacral nerve modulation should be more widely considered as an effective treatment strategy for patients with faecal incontinence following LAR.

Recovery after colonic surgery is invariably delayed by disturbed gut motility. It is commonly assumed that colonic motility becomes quiescent after surgery, but this hypothesis has not been evaluated rigorously. This study quantified colonic motility through the early postoperative period using high-resolution colonic manometry.

Fibre-optic colonic manometry was performed continuously before, during and after surgery in the left colon and rectum of patients undergoing right hemicolectomy, and in healthy controls. Motor events were characterized by pattern, frequency, direction, velocity, amplitude and distance propagated.

Eight patients undergoing hemicolectomy and nine healthy controls were included in the study. Colonic motility became markedly hyperactive in all operated patients, consistently dominated by cyclic motor patterns. Onset of cyclic motor patterns began to a minor extent before operation, occurring with increasing intensity nearer the time of surgery; the mean(s.d.) active duration was 12(7) per cent over 3 h before operation and 43(17) per cent within 1 h before surgery (P = 0.024); in fasted controls it was 2(4) per cent (P < 0·001). After surgery, cyclic motor patterns increased markedly in extent and intensity, becoming nearly continuous (active duration 94(13) per cent; P < 0·001), with peak frequency 2-4 cycles per min in the sigmoid colon. This postoperative cyclic pattern was substantially more prominent than in non-operative controls, including in the fed state (active duration 27(20) per cent; P < 0·001), and also showed higher antegrade velocity (P < 0·001).

Distal gut motility becomes markedly hyperactive with colonic surgery, dominated by cyclic motor patterns. This hyperactivity likely represents a novel pathophysiological aspect of the surgical stress response. Hyperactive motility may contribute to gut dysfunction after surgery, potentially offering a new therapeutic target to enhance recovery.

The purpose of this review is to highlight current and newer therapeutic approaches to treat fecal incontinence in patients who do not respond to conservative measures.

Neurostimulation techniques, injection of bulking agents, and radiofrequency energy delivery to the anal canal have been proposed and tested for fecal incontinence over the last decade. Sacral stimulation is both effective and durable and is now the most popular of the invasive techniques whereas percutaneous tibial stimulation, radiofrequency energy, and bulking agents are either less effective or their evaluation has been handicapped by suboptimal study designs. The precise indications for the new vaginal control device and anal plugs remain to be established. The magnetic anal sphincter is disappointing. Stem cell therapy is a potentially exciting approach, which is in its infancy. There continues to be an unmet need for innovative approaches to patients with fecal incontinence who do not respond to conservative measures. The efficacy of current and future therapies should be assessed using criteria more stringent than has been used in the past to provide a more realistic assessment of meaningful efficacy.

The regulation of gastrointestinal motility encompasses several overlapping mechanisms including highly regulated and coordinated neurohormonal circuits. Various feedback mechanisms or "brakes" have been proposed. While duodenal, jejunal, and ileal brakes are well described, a putative distal colonic brake is less well defined. Despite the high prevalence of colonic motility disorders, there is little knowledge of colonic motility owing to difficulties with organ access and technical difficulties in recording detailed motor patterns along its entire length. The motility of the colon is not under voluntary control. A wide range of motor patterns is seen, with long intervals of intestinal quiescence between them. In addition, the use of traditional manometric catheters to record contractile activity of the colon has been limited by the low number of widely spaced sensors, which has resulted in the misinterpretation of colonic motor patterns. The recent advent of high-resolution (HR) manometry is revolutionising the understanding of gastrointestinal motor patterns. It has now been observed that the most common motor patterns in the colon are repetitive two to six cycles per minute (cpm) propagating events in the distal colon. These motor patterns are prominent soon after a meal, originate most frequently in the rectosigmoid region, and travel in the retrograde direction. The distal prominence and the origin of these motor patterns raise the possibility of them serving as a braking mechanism, or the "rectosigmoid brake," to limit rectal filling. This review aims to describe what is known about the "rectosigmoid brake," including its physiological and clinical significance and potential therapeutic applications.

The purpose of this clinical practice update expert review is to describe the key principles in the use of surgical interventions and device-aided therapy for managing fecal incontinence (FI) and defecatory disorders. The best practices outlined in this review are based on relevant publications, including systematic reviews and expert opinion (when applicable). Best Practice Advice 1: A stepwise approach should be followed for management of FI. Conservative therapies (diet, fluids, techniques to improve evacuation, a bowel training program, management of diarrhea and constipation with diet and medications if necessary) will benefit approximately 25% of patients and should be tried first. Best Practice Advice 2: Pelvic floor retraining with biofeedback therapy is recommended for patients with FI who do not respond to the conservative measures indicated above. Best Practice Advice 3: Perianal bulking agents such as intra-anal injection of dextranomer may be considered when conservative measures and biofeedback therapy fail. Best Practice Advice 4: Sacral nerve stimulation should be considered for patients with moderate or severe FI in whom symptoms have not responded after a 3-month or longer trial of conservative measures and biofeedback therapy and who do not have contraindications to these procedures. Best Practice Advice 5: Until further evidence is available, percutaneous tibial nerve stimulation should not be used for managing FI in clinical practice. Best Practice Advice 6: Barrier devices should be offered to patients who have failed conservative or surgical therapy, or in those who have failed conservative therapy who do not want or are not eligible for more invasive interventions. Best Practice Advice 7: Anal sphincter repair (sphincteroplasty) should be considered in postpartum women with FI and in patients with recent sphincter injuries. In patients who present later with symptoms of FI unresponsive to conservative and biofeedback therapy and evidence of sphincter damage, sphincteroplasty may be considered when perianal bulking injection and sacral nerve stimulation are not available or have proven unsuccessful. Best Practice Advice 8: The artificial anal sphincter, dynamic graciloplasty, may be considered for patients with medically refractory severe FI who have failed treatment or are not candidates for barrier devices, sacral nerve stimulation, perianal bulking injection, sphincteroplasty and a colostomy. Best Practice Advice 9: Major anatomic defects (eg, rectovaginal fistula, full-thickness rectal prolapse, fistula in ano, or cloaca-like deformity) should be rectified with surgery. Best Practice Advice 10: A colostomy should be considered in patients with severe FI who have failed conservative treatment and have failed or are not candidates for barrier devices, minimally invasive surgical interventions, and sphincteroplasty. Best Practice Advice 11: A magnetic anal sphincter device may be considered for patients with medically refractory severe FI who have failed or are not candidates for barrier devices, perianal bulking injection, sacral nerve stimulation, sphincteroplasty, or a colostomy. Data regarding efficacy are limited and 40% of patients had moderate or severe complications. Best Practice Advice 12: For defecatory disorders, biofeedback therapy is the treatment of choice. Best Practice Advice 13: Based on limited evidence, sacral nerve stimulation should not be used for managing defecatory disorders in clinical practice. Best Practice Advice 14: Anterograde colonic enemas are not effective in the long term for management of defecatory disorders. Best Practice Advice 15: The stapled transanal rectal resection and related procedures should not be routinely performed for correction of structural abnormalities in patients with defecatory disorders.

Sacral nerve stimulation (SNS) is increasingly popular in the management of faecal incontinence. This paper reports the first 10-year experience of SNS in the management of faecal incontinence at a tertiary referral centre. Data was collected in a prospectively maintained database.

In total 130 patients were referred. The majority were women (94%) under 75-year-old (98%). Seven patients were found to have full-thickness rectal prolapse at the initial work-up and proceeded to rectopexy. Eighty-three patients underwent temporary SNS testing with 73.5% positive outcome, of which 52 patients had permanent implant insertion. There were four failures of SNS (7%) following implantation despite successful temporary testing, seven infection, one lead migration and three post-operative pain/numbness. One patient subsequently developed colorectal cancer requiring SNS removal. A higher frequency of episodes of incontinence was associated with positive SNS outcome (p = 0.007). There was no significant association between age, sex, type of faecal incontinence, previous anorectal/pelvic surgery, colonoscopic or USS findings and the likelihood of successful SNS. Of the 52 patients with SNS implants, 27 patients were seen only once for follow-up; the remaining 25 patients were seen more than once - five of these were part of our initial cases of routine 6- and 12-monthly follow-up, 6 patients were seen for adjustment of voltages, whereas the remaining 14 patients were seen for complications of the implants. If the initial five patients were excluded, only 38% of patients would have been seen more frequently on an as-required basis.

SNS is a safe and effective option in the management of faecal incontinence. Of the initial work-up, endoscopy and examination-under-anaesthesia (EUA) or proctogram are essential and more likely to influence the likelihood of suitability of SNS testing. A patient-led drop-in approach to follow-up is feasible to allow patients to be seen on an as-required basis.

To assess the outcomes of sacral nerve stimulation in adults with chronic constipation.

Standardised methods and reporting of benefits and harms were used for all CapaCiTY reviews that closely adhered to PRISMA 2016 guidance. Main conclusions were presented as summary evidence statements with a summative Oxford Centre for Evidence-Based Medicine (2009) level.

Seven articles were identified, providing data on outcomes in 375 patients. Length of procedures and length of stay was not reported. Data on harms were inconsistently reported and heterogeneous, making estimates of harm tentative and imprecise. Morbidity rates ranged between 13 and 34%, with overall device removal rate between 8 and 23%. Although inconsistently reported, pooled treatment success was typically 57-87% for patients receiving permanent implants, although there was significant variation between studies. Patient selection was inconsistently documented. No conclusions could be drawn regarding particular phenotypes that responded favourably or unfavourably to sacral nerve stimulation.

Evidence supporting sacral nerve stimulation is derived from poor quality studies. Three methodologically robust trials are have reported since this review and all have all urged greater caution.