Low anterior resection syndrome is a common but underestimated complication after rectal cancer surgery that significantly impacts the quality of life of the surviving patient. It is characterised by symptoms such as faecal incontinence and voiding dysfunction and affects up to 90% of patients undergoing low anterior rectal resection. The aetiology of the syndrome is multifactorial with no clear determining factor. It includes the use of preoperative radiotherapy, the indication for a protective ileostomy, sphincteric lesions, nerve damage to the rectal autonomic plexuses, and changes in left colon motor function. Although various therapeutic modalities have been shown to be effective in the management of the symptoms of the syndrome, there is still no standard treatment or patient selection pattern. In this article, a critical review of the therapeutic possibilities for patients who have survived rectal surgery will be made.

Low anterior resection syndrome (LARS) is a challenging complication following sphincter-preserving rectal surgery, characterized by bowel dysfunctions such as urgency, frequency, and incontinence. This case series investigates the potential role of lactose intolerance in exacerbating LARS symptoms. Three patients who developed LARS after rectal resections showed persistent symptoms despite conventional management with bulking agents, physiotherapy, and loperamide. However, all three experienced significant improvement in symptomatology, reflected by reductions in their LARS scores, after eliminating cow's milk from their diets. These findings suggest a potential link between lactose intolerance, including possible late-onset forms, and LARS symptoms. This study highlights the effectiveness of dietary modifications, particularly lactose elimination, as a simple and non-invasive strategy for managing LARS. The findings also support the need for dietary screening processes and recommendations for milk substitutes to enhance clinical care. Further research is necessary to validate these observations and refine therapeutic strategies.

To validate the predictive power of newly developed magnetic resonance (MR) morphological and clinicopathological risk models in predicting low anterior resection syndrome (LARS) 6 months after anterior resection of middle and low rectal cancer (MLRC).

From May 2018 to January 2021, 236 patients with MLRC admitted to two hospitals (internal and external validation) were included. MR images, clinicopathological data, and LARS scores (LARSS) were collected. Tumor morphology data included longitudinal involvement length, maximum tumor diameter, proportion of tumor to circumference of the intestinal wall, tumor mesorectal infiltration depth, circumferential margin status, and distance between the tumor and anal margins. Pelvic measurements included anorectal angle, mesenterial volume (MRV), and pelvic volume. Univariate and multivariate logistic regression was used to obtain independent risk factors of LARS after anterior resection Then, the prediction model was constructed, expressed as a nomogram, and its internal and external validity was assessed using receiver operating characteristic curves.

The uni- and multivariate analysis revealed distance between the tumor and anal margins, MRV, pelvic volume, and body weight as significant independent risk factors for predicting LARS. From the nomogram, the area under the curve (AUC), sensitivity, and specificity were 0.835, 75.0 %, and 80.4 %, respectively. The AUC, sensitivity, and specificity in the external validation group were 0.874, 83.3 %, and 91.7 %, respectively.

This study shows that MR imaging and clinicopathology presented by a nomogram can strongly predict LARSS, which can then individually predict LARS 6 months after anterior resection in patients with MLRC and facilitate clinical decision-making.

We believe that our study makes a significant contribution to the literature. This method of predicting postoperative anorectal function by preoperative measurement of MRV provides a new tool for clinicians to study LARS.

With the rise of structured, remote follow-up of colorectal cancers, there is the potential risk of underdiagnosing and undermanaging low anterior resection syndrome (LARS). This cohort study aims to determine the rate of LARS and its patterns of care, with the aim of generating a risk-stratified management algorithm that can be employed for nurse-led follow-up.

Patients who underwent elective anterior resection for the management of colorectal cancer between 1 January 2017 and 31 December 2021 were sent quality-of-life questionnaires (EORTC-QLQ-CR29 and LARS score) and surveyed for LARS symptoms and management utilized.

Out of 70 patients who completed questionnaires, 71.4% had LARS and 42.9% had major LARS. The international Delphi consensus definition identified more patients (n = 50) with LARS than the LARS score (n = 41). Tumours located <8 cm from the anal verge, ULAR, and temporary stoma were predictive of major LARS on univariate analysis. However, only temporary stoma was predictive for LARS (OR 7.89 (1.15-53.95), P = 0.035) and majors LARS (8.14 (1.79-37.01), P = 0.007) on multivariate analysis. Forty-four percent of patients with LARS did not have input from any health professional for this condition. Consultation with specialist allied health and/or colorectal surgeons ranged from 4% to 22%.

Our study highlights that with the current remote follow-up system focused on cancer outcomes a significant proportion of patients with LARS are overlooked, resulting in the underutilization of relevant health professionals and management options. We propose a nurse-led management algorithm to address this issue while still minimizing surgical outpatient load.

Imaging techniques play a crucial role in the modern era of medicine, particularly in gastroenterology. Nowadays, various non-invasive and invasive imaging modalities are being routinely employed to evaluate different gastrointestinal (GI) diseases. However, many instrumental as well as clinical issues are arising in the area of modern GI imaging. This minireview article aims to briefly overview the clinical issues and challenges encountered in imaging GI diseases while highlighting our experience in the field. We also summarize the advances in clinically available diagnostic methods for evaluating different diseases of the GI tract and demonstrate our experience in the area. In conclusion, almost all imaging techniques used in imaging GI diseases can also raise many challenges that necessitate careful consideration and profound expertise in this field.

Over 90% of rectal cancer patients develop low anterior resection syndrome (LARS) after sphincter-preserving resection. The current globally recognized evaluation method has many drawbacks and its subjectivity is too strong, which hinders the research and treatment of LARS.

To evaluate the anorectal function after colorectal cancer surgery by quantifying the index of magnetic resonance imaging (MRI) defecography, and pathogenesis of LARS.

We evaluated 34 patients using the standard LARS score, and a new LARS evaluation index was established using the dynamic images of MRI defecography to verify the LARS score.

In the LARS score model, there were 10 (29.41%) mild and 24 (70.58%) severe cases of LARS. The comparison of defecation rate between the two groups was 29.36 ± 14.17% versus 46.83 ± 18.62% (P = 0.004); and MRI-rectal compliance (MRI-RC) score was 3.63 ± 1.96 versus 7.0 ± 3.21 (P = 0.001). Severe and mild LARS had significant differences using the two evaluation methods. There was a significant negative correlation between LARS and MRI-RC score (P < 0.001), and they had a negative correlation with defecation rate (P = 0.028).

MRI defecography and standard LARS score can both be used as an evaluation index to study the pathogenesis of LARS.

A common and debilitating complication of low anterior resection for rectal cancer is low anterior resection syndrome (LARS). As a multifactorial entity, LARS is poorly understood and challenging to treat. Despite this, prevention strategies are commonly overlooked. Our aim was to review the pathophysiology of LARS and explore current evidence on the efficacy and feasibility of prophylactic techniques.

A literature review was performed between [1st January 2000 to 1st October 2023] for studies which investigated preventative interventions for LARS. Mechanisms by which LARS develop are described, followed by a review of prophylactic strategies to prevent LARS. Medline, Cochrane, and PubMed databases were searched, 189 articles screened, 8 duplicates removed and 18 studies reviewed.

Colonic dysmotility, anal sphincter dysfunction and neorectal dysfunction all contribute to the development of LARS, with the complex mechanism of defecation interrupted by surgery. Transanal irrigation (TAI) and pelvic floor rehabilitation (PFR) have shown benefits in preventing LARS, but may be limited by patient compliance. Intraoperative nerve monitoring (IONM) and robotic-assisted surgery have shown some promise in surgically preventing LARS. Nerve stimulation and other novel strategies currently used in treatment of LARS have yet to be investigated in their roles prophylactically.

To date, there is a limited evidence base for all preventative strategies including IONM, RAS, PFP and TAI. These strategies are limited by either access (IONM, RAS and PFP) or acceptability (PFP and TAI), which are both key to the success of any intervention. The results of ongoing trials will serve to assess acceptability, while technological advancement may improve access to some of the aforementioned strategies.

A total mesorectal excision for rectal cancer-although nerve- and sphincter-sparing-can give rise to significant bowel symptoms, commonly referred to as low anterior resection syndrome (LARS). The exact pathophysiology of this syndrome still remains largely unknown, and the impact of radical surgery on colonic motility has only been scarcely investigated.

High-resolution colon manometry was performed in patients, 12-24 months after restoration of transit. Patients were divided into two groups: patients with major LARS and no/minor LARS, according to the LARS-score. Colonic motor patterns were compared, and the relationship of these patterns with the LARS-scores was investigated.

Data were analyzed in 18 patients (9 no/minor LARS, 9 major LARS). Cyclic short antegrade motor patterns did occur more in patients with major LARS (total: p = 0.022; post-bisacodyl: p = 0.004) and were strongly correlated to LARS-scores after administering bisacodyl (p &lt; 0.001). High amplitude propagating contractions (HAPC's) that started in the proximal colon and ended in the mid-section of the colon occurred significantly less in patients with major LARS compared with patients with no/minor LARS (p = 0.015).

The occurrence of more cyclic short antegrade motor patterns and less HAPC's (from the proximal to the mid-colon) is more prevalent in patients with major LARS. These findings help to understand the differences in pathophysiology in patients developing major versus no/minor bowel complaints after TME for rectal cancer.

Many patients after sphincter-preserving surgery experienced anorectal functional disturbances which were known as low anterior resection syndrome (LARS). Although many studies investigated LARS, there was inconsistency of their assessment tools and results. The aim of this systematic review was to elucidate the incidence and risk factors of LARS by a validated tool-LARS score.

A systematic literature search in Pubmed, Embase, and Cochrane Library was conducted in April 2020. Studies investigating patients who were evaluated by LARS score 1 year after their sphincter-preserving surgery due to rectal cancer were included. Meta-analysis of incidence was conducted using the double arcsine method. Meta-analysis of each risk factor was conducted using a random effects model.

A total of 50 studies were included. The pooled incidence of major LARS was 44% (95% CI 40-48%; I² = 88%; 36 studies). Long course neoadjuvant radiotherapy (OR 2.89, 95% CI 2.06-4.05; I² = 47%; P < 0.01; 10 studies), total mesorectal excision (TME) (OR 2.13, 95% CI 1.49-3.04; I² = 53%; P < 0.01; 7 studies), anastomotic leak (OR 1.98, 95% CI 1.34-2.93; I² = 39%; P < 0.01; 9 studies), and diverting stoma (OR 1.89, 95% CI 1.58-2.27; I² = 0%; P < 0.01; 13 studies) were associated with increased risk of major LARS. No significant difference was found in major LARS incidence between transanal TME and laparoscopic TME (OR 1.36, 95% CI 0.78-2.40; I² = 19%; P = 0.28; 4 studies). Pouch reconstruction failed to lower the risk of major LARS in long term (OR 1.43, 95% CI 0.88-2.33; I² = 70%; P = 0.29; 9 studies).

The incidence of major LARS after sphincter-preserving surgery is relatively high. Neoadjuvant radiotherapy, TME, anastomostic leak, and diverting stoma are major risk factors. No significant differences in postoperative anorectal functions were observed between transanal and laparoscopic TME. Pouch reconstruction was not found to be significantly beneficial to anorectal functions in long term.

With improvement of the oncological prognosis and more sphincter-preserving procedures for rectal cancer of the lower third, the functional sequelae of anterior rectal resection become more and more predominant and are summarized under the term low anterior resection syndrome (LARS).

In this narrative review the causes, associated factors, prevalence, diagnostics and treatment strategies are presented based on an evaluation of the international literature.

The central role of the rectum in the physiology of defecation and continence explains the frequency of symptoms following anterior rectal resection. In an unselected patient population a major LARS is to be expected in approximately 40% and a minor LARS in approximately 20%. The most important factor is the length of the remaining rectal stump. The diagnosis of LARS is made clinically and can be quantified by scores, especially by the LARS score. Treatment options range from patient counselling to stoma construction and a symptom-related, stepwise approach is generally accepted.

While the evidence for the causes, the quantification and determination of associated factors of LARS is good, the treatment options are based either on experience or on only few studies.

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.