Insufficient bowel preparation accounts for up to 42% of missed adenomas in colonoscopy. However, major analysis programs found no correlation between adenoma detection rate and the human-rated Boston Bowel Preparation Scale (BBPS), indicating limitations of the scale. We therefore aimed to develop an Open-Source Automatic Bowel Preparation Scale (OSABPS) based on artificial intelligence that is correlated to the polyp detection rate.

The OSABPS was trained on 50,000 frames from 20 colonoscopies from 3 hospitals. It involved quantifying the presence of fecal matter within the colonoscopy frames, using an approach termed the fecal ratio-the proportion of pixels identified as feces (F) relative to those identified as mucosal tissue (M) (OSABPS = F/M)-thereby making 0 the optimal score, indicating a perfect cleansing. The Youden J was used to set the threshold because it determines the optimal balance between sensitivity and specificity. The algorithm was then tested on 1405 colonoscopies from 3 hospitals (internal validation) and 5525 frames from a public colonoscopy database (Nerthus, external validation).

Internal validation: the OSABPS correlated significantly with the BBPS (Pearson r = -0.42, P < .001). A threshold of 0.09 OSABPS was determined using the Youden J. The polyp detection rate was higher for colonoscopies below the threshold of the Youden J (2-proportion z-test, P < .001). External validation: the OSABPS correlated significantly with the BBPS (Pearson r = -0.70, P < .001).

The OSABPS can automatically, instantly, and without human bias assess bowel preparation quality. Colonoscopies with an OSABPS of >0.09 should be considered for reexamination. The OSABPS's open-source nature allows free implementation.

Inadequate bowel preparation (BP) negatively affects diagnostic performance of colonoscopy. Most trials assessing adequacy of bowel preparation regimens have excluded patients affected by chronic kidney disease (CKD), especially patients on dialysis. This study aimed to assess the impact of dialysis on BP quality and adenoma detection rate (ADR) and identify factors related to quality of BP.

We retrospectively compared patient-specific, preparation-specific (preparation solution, preparation regimen (split-dose vs. 1-day preparation, outpatient preparation), and colonoscopy-specific data (indication, Boston Bowel Preparation Score [BBPS], sedation type, presence of adenoma or cancer) between 79 patients on dialysis and 158 matched controls. Adequate BP was defined as a BBPS score ≧2 in every colonic segment. Significant contributors to BP were assessed by logistic regression.

Despite matching, dialysis patients were significantly older (69.0 ± 11.9 vs 64.2 ± 14.6, P = 0.008) and less frequently women (30% vs 52%, P = 0.002). There was no significant difference in BP or ADR between patients on dialysis and controls (85% vs 89%, P = 0.39 and 35% vs 35%, P = 1.00, respectively). Older age ( P = 0.03), lower body mass index ( P = 0.03), type of BP regimen ( P <0.001), outpatient preparation ( P = 0.03), and residency in residential care ( P = 0.05) were significantly associated with BP adequacy. According to the logistic regression model, split-dose regimen was the main predictor of adequate BP ( P <0.001, odds ratio 3.1 [1.65-5.81]).

Safe and adequate BP is achievable in dialysis patients. Bowel preparation regimen rather than treatment with dialysis influences BP quality. Split-dose preparation remains the most important determinant of adequate BP for colonoscopy, irrespective of regimen.

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

This document is an update to the 2014 recommendations for optimizing the adequacy of bowel cleansing for colonoscopy from the US Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy. The US Multi-Society Task Force developed consensus statements and key clinical concepts addressing important aspects of bowel preparation for colonoscopy. The majority of consensus statements focus on individuals at average risk for inadequate bowel preparation. However, statements addressing individuals at risk for inadequate bowel preparation quality are also provided. The quality of a bowel preparation is defined as adequate when standard screening or surveillance intervals can be assigned based on the findings of the colonoscopy. We recommend the use of a split-dose bowel preparation regimen and suggest that a 2 L regimen may be sufficient. A same-day regimen is recommended as an acceptable alternative for individuals undergoing afternoon colonoscopy, but we suggest that a same-day regimen is an inferior alternative for individuals undergoing morning colonoscopy. We recommend limiting dietary restrictions to the day before a colonoscopy, relying on either clear liquids or low-fiber/low-residue diets for the early and midday meals. We suggest the adjunctive use of oral simethicone for bowel preparation before colonoscopy. Routine tracking of the rate of adequate bowel preparations at the level of individual endoscopists and at the level of the endoscopy unit is also recommended, with a target of >90% for both rates.

We aimed to evaluate whether direct access colonoscopy (DAC) is noninferior to office-scheduled colonoscopy (OSC) for achieving successful colonoscopy.

DAC may improve access to colonoscopy. We developed an algorithm assessing eligibility, risk for inadequate preparation, and need for nursing/navigator assistance.

This was a retrospective, single-center study of DAC and OSC patients from June 5, 2018, to July 31, 2019. Patients were 45 to 75 years old with an indication of screening or surveillance. A successful colonoscopy met 3 criteria: complete colonoscopy (cecum, anastomosis, or ileum), adequate preparation (Boston Score ≥2/segment), and performed <90 days from initial patient contact. Unsuccessful colonoscopy did not meet ≥1 criteria. Secondary end points included days to successful colonoscopy, preparation quality, polyp detection, and 10-year recall rate. Noninferiority against risk ratio value of 0.85 was tested using 1-sided alpha of 0.05.

A total of 1823 DAC and 828 OSC patients were eligible. DAC patients were younger, with a greater proportion of black patients and screening indications. For the outcome of successful colonoscopy, DAC was noninferior to OSC (DAC vs. OSC: 62.7% vs. 57.1%, RR 1.16, 95% LCL 1.09, P =0.001). For DAC, days to colonoscopy were fewer, and likelihood of 10-year recall after negative screening greater. Boston Score and polyp detection were similar for groups. Black patients were less likely to achieve successful colonoscopy; otherwise, groups were similar. For unsuccessful colonoscopies, proportionally more DAC patients canceled or no-showed while more OSC patients scheduled >90 days. DAC remained noninferior to OSC at 180 days.

DAC was noninferior to OSC for achieving successful colonoscopy, comparing similarly in quality and efficiency outcomes.

Despite lower patient adherence, the overnight split-dose (SD) intestinal preparation regimen is currently recommended for early morning colonoscopies. Using low-volume preparation, we compared performance of a "day before late" (DBL) regimen, with the whole preparation taken between 8.30 pm and midnight on the day before the endoscopic procedure vs the overnight SD regimen for colonoscopies scheduled between 8 am and 10 am.

Patients were randomized to the DBL group (n = 162) or SD group (n = 158). The SD group took the second dose 5 hours before colonoscopy. Successful bowel cleansing, defined as an overall Boston Bowel Preparation Score ≥ 3, safety, compliance and tolerability were assessed in the two groups.

The DBL regimen failed to demonstrate non-inferiority compared with the SD regimen in terms of successful bowel cleansing (DBL, 88.2 % vs SD, 98.1%, P < 0.001). Subgroup analysis on colonoscopies before 9 am showed BBPS ≥ 3 rates of 94.6% and 100% in the DBL and SD groups, respectively P = 0.126). The two regimens showed similar compliance and tolerability. Compared with SD patients (25.5%), a lower proportion of DBL patients (13.9%) reported fear of incontinence during the journey to the hospital ( P = 0.01).

Albeit more tolerable, the DBL regimen was less effective than the SD regimen with regard to successful bowel cleansing for colonoscopies between 8 am and 10 am. Subgroup analysis on colonoscopies scheduled before 9 am showed that the two regimens have similar efficacy, suggesting that the DBL regimen may be a valuable alternative to the SD regimen for very early morning colonoscopies.

Colonoscopy is a diagnostic and therapeutic procedure that reduces colorectal cancer incidence and mortality but requires adequate bowel cleansing for high-quality examination. Past studies have suggested cirrhosis as a risk factor for worse bowel preparation.

We carried out a match-controlled retrospective study evaluating patients with and without cirrhosis who underwent outpatient screening colonoscopies to assess the effect of cirrhosis and portal hypertension complications on preparation quality and endoscopic measures. We also did a subgroup analysis excluding patients with obesity.

We examined 1464 patients with cirrhosis and matched controls. Cirrhotic patients had lower mean Boston Bowel Preparation Scale (BBPS) scores and slower cecal intubation times. We found a single point increase in the Model for End-stage Liver Disease (MELD) score, as well as ascites, hepatic encephalopathy, and variceal hemorrhage were all associated with a longer cecal intubation time. Subgroup analysis excluding patients with obesity again found a significantly lower BBPS score and longer cecal intubation time while also finding a 24% drop in polyp detection.

Patients with cirrhosis have worse BBPS scores and longer cecal intubation times. Nonobese cirrhotic patients additionally have a lower polyp detection rate. Portal hypertension complications were associated with worsened preparation quality and longer cecal intubation times. Each incremental increase in MELD score lengthened cecal intubation time. These findings support a more aggressive bowel preparation strategy for patients with cirrhosis, especially patients with severe disease or portal hypertension complications.

The adenoma detection rate (ADR), recognized as a surrogate marker for colorectal cancer (CRC) incidence and mortality reduction, is closely linked to the efficacy of bowel cleansing. However, there is a dearth of evidence examining the impact on ADR when using 2 distinct very-low-dose bowel cleansing products. This study sought to compare ADR in an immunochemical fecal occult blood test (iFOBT)-based organized screening program by using 1 L of polyethylene glycol plus ascorbate (1L-PEGA) versus sodium picosulfate with magnesium citrate (SPMC), both administered in a split-dose regimen.

We conducted a comparative, parallel, randomized, noninferiority, and low-intervention clinical trial targeting individuals from a population CRC screening program aged 50 to 69 years with a positive iFOBT result scheduled for a workup colonoscopy in the morning. Participants were randomized to either 1L-PEGA or SPMC for bowel cleansing. The main outcome was ADR, whereas secondary outcomes were bowel preparation quality, safety, tolerability, and satisfaction.

A total of 1002 subjects, 501 were included in each group. There were no differences between groups with respect to pooled ADR (SPMC, 56.5% [95% CI, 52.1-60.8]; 1L-PEGA, 53.7% [95% CI, 49.3-58.0]; relative risk, .95 [95% CI, .85-1.06]); therefore, SPMC demonstrated noninferiority in ADR compared with 1L-PEGA (difference, 2.8%; 2-sided 95% lower confidence limit, -3.4). In addition, there were no significant differences in mean lesions regardless of size and location between arms. Bowel preparation favored 1L-PEGA (96.2% vs 89.2%, P < .001), whereas SPMC exhibited significantly higher safety and tolerability, as shown by fewer nonserious treatment-emergent adverse events.

SPMC emerged as a noninferior laxative compared with 1L-PEGA concerning ADR. Despite the superior bowel preparation quality associated with 1L-PEGA, the safety, tolerability, and overall satisfaction of participants were higher with SPMC. (Clinical trial registration number: EudraCT: 2019-003186-18.).

Colonoscopy is widely used as a diagnostic and preventive procedure for colorectal diseases. The most recent guidelines advocate the use of a low-residue diet (LRD) for bowel preparation before colonoscopy. LRD duration varies considerably, with recommended 1-day and multiple-day regimens in clinical practice.

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched multiple databases for randomized controlled trials (RCTs) and analyzed the outcomes using a fixed-effects model.

Six RCTs with 2,469 subjects were included in this study. The rates of adequate bowel preparation for 1-day and >1-day were 87.2% and 87.1%, respectively. No statistically significant differences were observed between the 1-day and >1-day LRD in adequate bowel preparation (odds ratio [OR], 1.03; 95% confidence interval [CI], 0.76-1.41; p=0.84; I2=0%), polyp detection rate (OR, 0.91; 95% CI, 0.76-1.09; p=0.29; I2=16%), adenoma detection rate (OR, 0.87; 95% CI, 0.71-1.08; p=0.21; I2=0%), and withdrawal time (mean difference, -0.01; 95% CI, -0.25 to 0.24; p=0.97; I2=63%).

The efficacy of 1-day and multiple-day LRD is comparable in achieving satisfactory bowel preparation, highlighting their similar impact on the detection of polyps and adenomas during colonoscopy.

Colorectal cancer (CRC) causes substantial morbidity and mortality internationally. In Hungary, the incidence and mortality of CRC are among the world's highest. Fortunately, CRC is a highly preventable disease, since there is a long asymptomatic phase before neoplastic transformation. Numerous countries have instituted programs for CRC screening. However, Hungary did not implement population-based screening programs until December 2018, consisting of a voluntary 2-step screening program based on the fecal immunochemical test (FIT) and if positive, referral to colonoscopy. Asymptomatic individuals aged over 50 years were invited to participate in the 2-step program. This study aims to analyze the results of these colonoscopies and raise public awareness of the CRC disease process and prevention, especially in Hungary.

Various literature sources were reviewed, and external information was gathered and consolidated based on CRC etiopathogenesis, management options, screening options, cost, benefits, modalities, and quality control. Semmelweis University Department of Internal Medicine and Hematology's database was accessed for the cross-sectional study results of 168 screening colonoscopies within the 2-step program from 2019 to 2020. I quantified and compared the results obtained during the colonoscopies with that of said literature within Hungary and worldwide.

Colonoscopy was performed in 168 patients of average age 63.4 years. The incidence of CRCs in the population was 4.76%. Among the CRC cases, 75% were in the rectosigmoid area and 25% were in the remaining colon. The total adenoma detection rate (ADR) in the study was 57.1%, higher than the recommended 25% for adequate screening colonoscopy. The total number of resected polyps was 270; 8.1% were adenomas with high-grade dysplasia and 0.76% contained CRC. Out of the 185 resected adenomas, 141 were tubular, 34 were tubulovillous, and 10 were villous. Adenoma localizations included 14.6% rectum, 38.4% sigmoid, 11.9% descending colon, 8.6% transverse colon, 17.8% ascending colon, and 8.6% cecum. The average age of CRC patients was 63.9 years (range, 56-68 years) with a slight female predominance (5 females, 3 males). The ADR of the different endoscopists did not seem to correlate with experience. Optimal participation rate of the screening program would be >60%. Population outreach through mailed FIT is evidence-based and shown to increase CRC screening rates in underserved populations.

Hungary would benefit immensely in most aspects from mandatory, population-based CRC screening with this 2-step program. This alternative is proposed in lieu of 1-step screening, because of the limited capacity for colonoscopy in the country and the limited participation rates in the screened population. To reach maximum cost-benefit, the participation rate of the screened population must be >60%, with >80% of FIT positive test results being referred to colonoscopy. Consolidation and distribution of the screening program through population outreach will bring about substantial reductions in mortality from CRC. Further studies are warranted on the feasibility and sustainability of this 2-step program.

Colonoscopy plays a crucial role in the early diagnosis and treatment of colorectal cancer. Adequate bowel preparation is essential for clear visualization of the colonic mucosa and lesion detection. However, inadequate bowel preparation is common in patients with constipation, and there is no standardized preparation protocol for these patients. This study aimed to explore the effectiveness and tolerability of a pre-colonoscopy combination regimen of linaclotide and polyethylene glycol (PEG).

In this prospective, single-center, randomized controlled trial, 322 participants were divided into two groups: a 3-L PEG + 870-μg linaclotide group (administered as a single dose for 3 days) and a 4-L PEG group. The primary endpoints were the Boston Bowel Preparation Scale (BBPS) score and the rate of adequate and excellent bowel preparation. Secondary endpoints were the rates of detection of colonic adenomas and polyps, cecal intubation rates, colonoscopy time, adverse reactions, patient satisfaction, and physician satisfaction.

The study included 319 patients. The 3-L PEG + linaclotide group showed significantly higher rates of adequate and excellent bowel preparation than the 4-L PEG group (89.4% vs 73.6% and 37.5% vs 25.3%, respectively; P < 0.05). The mean BBPS score for the right colon in the 3-L PEG + linaclotide group was significantly higher than that in the 4-L PEG group. There were no significant between-group differences regarding the detection rates of colonic polyps and adenomas (44.4% vs 37.7% and 23.1% vs 20.1%, respectively; P > 0.05). There were no significant between-group differences regarding cecal intubation rates, colonoscopy operation, and withdrawal times. However, patient tolerance and sleep quality were better in the 3-L PEG + linaclotide group.

The combination of 3-L PEG and 870-μg linaclotide, because of its lower volume of intake, can be considered as an alternative bowel preparation regimen for constipated patients undergoing colonoscopy, especially for the elderly.

Artificial intelligence (AI) has emerged as a promising tool for detecting and characterizing colorectal polyps during colonoscopy, offering potential enhancements in traditional colonoscopy procedures to improve outcomes in patients with inadequate bowel preparation.

This study aimed to assess the impact of an AI tool on computer-aided detection (CADe) assistance during colonoscopy in this population.

This case-control study utilized propensity score matching (PSM) for age, sex, race, and colonoscopy indication to analyze a database of patients who underwent colonoscopy at a single tertiary referral center between 2017 and 2023. Patients were excluded if the procedure was incomplete or aborted owing to poor preparation. The patients were categorized based on the use of AI during colonoscopy. Data on patient demographics and colonoscopy performance metrics were collected. Univariate and multivariate logistic regression models were used to compare the groups.

After PSM patients with adequately prepped colonoscopies (n = 1466), the likelihood of detecting hyperplastic polyps (OR = 2.0, 95%CI 1.7-2.5, p < 0.001), adenomas (OR = 1.47, 95%CI 1.19-1.81, p < 0.001), and sessile serrated polyps (OR = 1.90, 95%CI 1.20-3.03, p = 0.007) significantly increased with the inclusion of CADe. In inadequately prepped patients (n = 160), CADe exhibited a more pronounced impact on the polyp detection rate (OR = 4.34, 95%CI 1.6-6.16, p = 0.049) and adenomas (OR = 2.9, 95%CI 2.20-8.57, p < 0.001), with a marginal increase in withdrawal and procedure times.

This study highlights the significant improvement in detecting diminutive polyps (< 5 mm) and sessile polyps using CADe, although notably, this benefit was only seen in patients with adequate bowel preparation. In conclusion, the integration of AI in colonoscopy, driven by artificial intelligence, promises to significantly enhance lesion detection and diagnosis, revolutionize the procedure's effectiveness, and improve patient outcomes.

Accurate bowel preparation assessment is essential for determining colonoscopy screening intervals. Patients with suboptimal bowel preparation are at a high risk of missing >5 mm adenomas and should undergo an early repeat colonoscopy. In this study, we used artificial intelligence (AI) to evaluate bowel preparation and validated the ability of the system to accurately identify patients who are at high risk of having >5 mm adenomas missed due to inadequate bowel preparation.

This prospective, single-center, observational study was conducted at the Eighth Affiliated Hospital, Sun Yat-sen University, from October 8, 2021, to November 9, 2022. Eligible patients who underwent screening colonoscopy were consecutively enrolled. The AI assessed bowel preparation using the e-Boston Bowel Preparation Scale (e-BBPS) while endoscopists made evaluations using BBPS. If both BBPS and e-BBPS deemed preparation adequate, the patient immediately underwent a second colonoscopy; otherwise, the patient underwent bowel re-cleansing before the second colonoscopy.

Among the 393 patients, 72 adenomas >5 mm in size were detected; 27 adenomas >5 mm in size were missed. In unqualified-AI patients, the >5 mm adenoma miss rate (AMR) was significantly higher than in qualified-AI patients (35.71% vs 13.19% [P = .0056]; odds ratio [OR], .2734 [95% CI, .1139-.6565]), as were the AMR (50.89% vs 20.79% [P < .001]; OR, .2532 [95% CI, .1583-.4052]) and >5 mm polyp miss rate (35.82% vs 19.48% [P = .0152]; OR, .4335 [95% CI, .2288-.8213]).

This study confirmed that patients classified as inadequate by AI exhibited an unacceptable >5 mm AMR, providing key evidence for implementing AI in guiding bowel re-cleansing and potentially standardizing future colonoscopy screening. (Clinical trial registration number: NCT05145712.).

Adequate bowel preparation is paramount for a high-quality screening colonoscopy. Despite the importance of adequate bowel preparation, there is a lack of large studies that associated the degree of bowel preparation with long-term colorectal cancer outcomes in screening patients.

In a large population-based screening program database in Austria, quality of bowel preparation was estimated according to the Aronchick Scale by the endoscopist (excellent, good, fair, poor, and inadequate bowel preparation). We used logistic regression to assess the influence of bowel preparation on the detection of different polyp types and the interphysician variation in bowel preparation scoring. Time-to-event analyses were performed to investigate the association of bowel preparation with postcolonoscopy colorectal cancer (PCCRC) death.

A total of 335,466 colonoscopies between January 2012 and follow-up until December 2022 were eligible for the analyses. As compared with excellent bowel preparation, adenoma detection was not significantly lower for good bowel preparation (odds ratio 1.01, 95% confidence interval [CI] 0.9971-1.0329, P = 0.1023); however, adenoma detection was significantly lower in fair bowel preparation (odds ratio 0.97, 95% CI 0.9408-0.9939, P = 0.0166). Individuals who had fair or lower bowel preparation at screening colonoscopy had significantly higher hazards for PCCRC death (hazard ratio for fair bowel preparation 2.56, 95% CI 1.67-3.94, P < 0.001).

Fair bowel preparation on the Aronchick Scale was not only associated with a lower adenoma detection probability but also with increased risk of PCCRC death. Efforts should be made to increase bowel cleansing above fair scores.

Adenoma detection rate and interval colon cancer rates are associated with bowel preparation quality. The US Multisociety Task Force recommends repeat colonoscopy for individuals with inadequate bowel preparation (IBP) within 1 year. However, little is known regarding the rate and associated factors of repeat colonoscopy after IBP.

Individuals undergoing colonoscopy for screening, surveillance, positive fecal immunohistochemistry test, and virtual colonoscopy at the Minneapolis Veterans Affairs Medical Center from January 2016 to October 2021 were included. IBP was classified based on Boston Bowel Preparation Scale score or Aronchick scale.

A total of 10,466 individuals were included, of which 571 (5.5%) had IBP. Repeat colonoscopy within 1 year was recommended for 485 individuals (84.9%); 287 (59.2%) were completed within this time period and 126 (26.0%) never underwent repeat colonoscopy. Proximity to the endoscopy center was associated with a higher rate of repeat colonoscopy within 1 year (61.7% vs 51.0%, P = .02). Current smoking status was associated with a lower rate of repeat colonoscopy within 1 year (25.8% vs 35.9%, P = .02). There were no differences in age, sex, race, inflammatory bowel disease diagnosis, or opioid or anticoagulation use with adherence to repeat colonoscopy within 1 year. There was no difference in adherence to a timely repeat colonoscopy from 1 year before the COVID-19 pandemic (58.9%) vs 1 year postpandemic (59.9%).

The rate of IBP was 5.5%. Only 59.2% of those with IBP underwent recommended repeat colonoscopy within 1 year, and 26.0% never underwent repeat colonoscopy. Additional efforts are needed to ensure that individuals with IBP return for timely repeat colonoscopy.

Colorectal cancer is one of the predominant tumors in the world, primarily generated by a progression from polyp to cancer which can last several years, giving a great opportunity to the scientific community for its prevention by screening programs that can be done with invasive and non-invasive tests. In this issue, Lopes et al show us an excellent review of screening, its options, its advantages and disadvantages.

The incidence and mortality of colorectal cancer (CRC) have decreased through regular screening colonoscopy, surveillance, and endoscopic treatment. However, CRC can still be diagnosed after negative colonoscopy. Such CRC is called interval CRC and accounts for 1.8-9.0% of all CRC cases. Most cases of interval CRC originate from missed lesions and incompletely resected lesions. Interval CRC can be minimized by improving the quality of colonoscopy. This has led to a growing interest in and demand for high-quality colonoscopy. It is important to reduce the risk of CRC and its associated mortality by improving the quality of colonoscopy. In this review article, we provide an overview of colonoscopy quality indicators, including bowel preparation adequacy, the cecal intubation rate, the adenoma detection rate, the colonoscopy withdrawal time, appropriate polypectomy, and complication of the procedure. Because colonoscopy is a highly endoscopist-dependent procedure, colonoscopists should be well-acquainted with quality indicators and strive to apply them in daily clinical practice for the prevention of CRC.

The effectiveness of colonoscopy is limited by the adequacy of bowel preparation. Nurses are essential in providing bowel cleansing agents and instructions for hospitalized patients before colonoscopy. This study aims to assess and improve the knowledge of nurses on bowel preparation for inpatient colonoscopy. Participants were asked to complete the survey before and after completing an educational module. The module and survey questions were placed in the NetLearning environment of the hospital intranet. A minimum post-test score of 80% was required to pass the course. A total of 1,107 nurses participated in the survey. Overall, the average score improved from 87% to 93% after the module (p < .0495). Knowledge of the different ways of consuming bowel cleansing agents improved from 54.3% to 83.6% (p = .0001). Only 56.2% of nurses knew how to carry out a split-dose bowel preparation regimen, which increased to 80.1% after the educational module (p = .0001). Nurses' knowledge about the different ways of consuming bowel cleansing agents before colonoscopy and the split-dose regimen is inadequate. A simple online educational module significantly improved the knowledge of nurses on bowel preparation for colonoscopy.

Despite recent advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable primarily due to high recurrence and liver metastasis rates. Fluorescence molecular imaging technologies, combined with specific probes, have gained prominence in facilitating real-time tumor resection guided by fluorescence. Hepatocyte growth factor (HGF) is overexpressed in CRC, but the advancement of HGF fluorescent probes has been impeded by the absence of effective HGF-targeting small-molecular ligands. Herein, we present the targeted capabilities of the novel V-1-GGGK-MPA probe labeled with a near-infrared fluorescent dye, which targets HGF in CRC. The V-1-GGGK peptide exhibits high specificity and selectivity for HGF-positive in vitro tumor cells and in vivo tumors. Biodistribution analysis of V-1-GGGK-MPA revealed tumor-specific accumulation with low background uptake, yielding signal-to-noise ratio (SNR) values of tumor-to-colorectal >6 in multiple subcutaneous CRC models 12 h postinjection. Quantitative analysis confirmed the probe's high uptake in SW480 and HT29 orthotopic and liver metastatic models, with SNR values of tumor-to-colorectal and -liver being 5.6 ± 0.4, 4.6 ± 0.5, and 2.1 ± 0.3, 2.0 ± 0.5, respectively, enabling precise tumor visualization for surgical navigation. Pathological analysis demonstrated the excellent tumor boundaries discrimination capacity of the V-1-GGGK-MPA probe at the molecular level. With its rapid tumor targeting, sustained tumor retention, and precise tumor boundary delineation, V-1-GGGK-MPA merges as a promising HGF imaging agent, enriching the toolbox of intraoperative navigational fluorescent probes for CRC.

This study aimed to compare the performance of standard-definition white-light endoscopy (SD-WL), high-definition white-light endoscopy (HD-WL), and high-definition narrow-band imaging (HD-NBI) in detecting colorectal lesions in the Chinese population.

This was a multicenter, single-blind, randomized, controlled trial with a non-inferiority design. Patients undergoing endoscopy for physical examination, screening, and surveillance were enrolled from July 2017 to December 2020. The primary outcome measure was the adenoma detection rate (ADR), defined as the proportion of patients with at least one adenoma detected. The associated factors for detecting adenomas were assessed using univariate and multivariate logistic regression.

Out of 653 eligible patients enrolled, data from 596 patients were analyzed. The ADRs were 34.5% in the SD-WL group, 33.5% in the HD-WL group, and 37.5% in the HD-NBI group (P=0.72). The advanced neoplasm detection rates (ANDRs) in the three arms were 17.1%, 15.5%, and 10.4% (P=0.17). No significant differences were found between the SD group and HD group regarding ADR or ANDR (ADR: 34.5% vs. 35.6%, P=0.79; ANDR: 17.1% vs. 13.0%, P=0.16, respectively). Similar results were observed between the HD-WL group and HD-NBI group (ADR: 33.5% vs. 37.7%, P=0.45; ANDR: 15.5% vs. 10.4%, P=0.18, respectively). In the univariate and multivariate logistic regression analyses, neither HD-WL nor HD-NBI led to a significant difference in overall adenoma detection compared to SD-WL (HD-WL: OR 0.91, P=0.69; HD-NBI: OR 1.15, P=0.80).

HD-NBI and HD-WL are comparable to SD-WL for overall adenoma detection among Chinese outpatients. It can be concluded that HD-NBI or HD-WL is not superior to SD-WL, but more effective instruction may be needed to guide the selection of different endoscopic methods in the future. Our study's conclusions may aid in the efficient allocation and utilization of limited colonoscopy resources, especially advanced imaging technologies.

This meta-analysis aimed to comprehensively explore the risk factors for inadequate bowel preparation (IBP).

We searched the Embase, PubMed, Web of Science, and The Cochrane Library databases up to August 24, 2023, to identify observational studies and randomized controlled trials (RCTs) that examined risk factors for IBP. A random effects model was used to pool the adjusted odds ratios and 95% confidence intervals.

A total of 125 studies (91 observational studies, 34 RCTs) were included. Meta-analyses of observational studies revealed that three preparation-related factors, namely, characteristics of last stool (solid or brown liquid), incomplete preparation intake, and incorrect diet restriction, were strong predictors of IBP. The other factors were moderately correlated with IBP incidence, including demographic variables (age, body mass index, male sex, Medicaid insurance, and current smoking), comorbidities (diabetes, liver cirrhosis, psychiatric disease, Parkinson's disease, previous IBP, poor mobility, inpatient, and Bristol stool form 1/2), medications (tricyclic antidepressants, opioids, antidepressants, narcotics, antipsychotics, and calcium channel blockers), and preparation-related factors (preparation-to-colonoscopy interval not within 3 to 5/6 h, nonsplit preparation, and preparation instructions not followed). No colonoscopy indications were found to be related to IBP. Meta-analyses of RCTs showed that education, constipation, stroke/dementia, and discomfort during preparation were also moderately associated with IBP. Most of the other findings were consistent with the pooled results of observational studies. However, primarily due to imprecision and inconsistency, the certainty of evidence for most factors was very low to moderate.

We summarized five categories of risk factors for IBP. Compared to demographic variables, comorbidities, medications, and colonoscopy indications, preparation-related elements were more strongly associated with IBP. These findings may help clinicians identify high-risk individuals and provide guidance for IBP prevention.

Inadequate bowel preparation can result in decreased diagnostic accuracy and therapeutic safety of colonoscopy for colon cancer screening. The Boston Bowel Preparation Scale (BBPS) has been used to assess the quality of bowel preparation. Glucagon-like peptide-1 receptor agonists (GLP-1RA) are commonly used medications for diabetes mellitus and obesity that are known to delay gastrointestinal motility. We hypothesized that the use of GLP-1RA would be associated with decreased quality of bowel preparation.

We performed a retrospective cohort study of patients who underwent screening or surveillance colonoscopy at a large academic medical center between December 2021 and December 2022. We included patients taking any GLP-1RA for diabetes or obesity during colonoscopy defined as our cases, and patients who were prescribed GLP-1RA at one point but not within 3 months of colonoscopy defined as our controls. We excluded patients on any promotility or antimotility agents and those without BBPS recorded on their procedure report. Independent t test assessed statistical differences in the case and control groups to compare the quality of bowel preparation for continuous variables, and the χ 2 test was used for categorical variables. Multivariate linear regression including diabetes as a covariate was also performed for continuous variables, and multivariate logistic regression was performed for categorical variables.

A total of 446 patients were included in the study, comprising 265 (59%) cases and 181 controls (41%). There were no statistically significant differences between groups at baseline except for the diagnosis of diabetes ( P = 0.001) with a higher proportion of patients with diabetes in the cases. The mean BBPS was significantly higher in controls (7.0 ± 1.9 vs 7.5 ± 2.4, P = 0.046) when controlling for diabetes. The percentage of patients with a total BBPS score of <5 was significantly higher in cases (15.5% vs 6.6%, P = 0.01). The proportion of patients who required a repeat colonoscopy due to poor bowel preparation was also significantly higher in cases (18.9% vs 11.1%, P = 0.041).

The use of GLP-1RA was associated with a statistically significantly lower quality of bowel preparation, with additional clinical significance given a notable difference in the need for a repeat colonoscopy. It will be essential to understand the cumulative effect of medications that may delay gastric emptying on the quality of bowel preparation to better understand the appropriate measures and counseling that need to be taken before undergoing outpatient colonoscopies.

In this study, we investigated the relationship between the cecal intubation time (CIT) and the form and method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure using an endoscopic position detection unit (UPD), with reference to various factors [age, sex, body mass index (BMI), history of abdominal and pelvic surgery, and diverticulum]. A total of 152 patients underwent colonoscopy with UPD. The mean age was 66.9 ± 12.4 years, and the male to female ratio was 3.6:1. The average CIT time was 14.3 ± 8.2 min. Age, number of experienced endoscopies, history of abdominal and pelvic surgery, BMI, and diverticulum were associated with prolonged CIT; SDJ passage pattern was straight: 8.6 ± 5.0, alpha loop: 11.8 ± 5.6, puzzle ring-like loop: 20.2 ± 5.0, reverse alpha loop: 22.4 ± 9.7, and other loop: 24.7 ± 10.5. The hepatic flexure passing method was in the following order: right rotation maneuver: 12.6 ± 6.6, push maneuver: 15.1 ± 5.9, and right rotation with positional change maneuver: 20.5 ± 7.2. In conclusion, colonoscopy with UPD revealed an association between CIT and SDJ passage pattern and hepatic flexure passing method.

Background and study aims The aim of this study was to assess the effect of an educational video on the quality of bowel preparation of patients from a UK population attending for their first colonoscopy. Patients and methods A prospective, endoscopist-blinded trial with 1:1 allocation was performed. Patients referred for their first colonoscopy were recruited between February 2019 and December 2019. All participants were prescribed Moviprep and received the trial site's standard written bowel preparation instructions, with the intervention group also receiving a bespoke educational video. Adequacy of bowel preparation (defined as a Boston Bowel Preparation Scale of ≥2 in each segment of the bowel) and polyp detection rates (PDRs) were compared. Fisher's chi squared test was utilized with P <0.05 as the threshold for significance. Results A total of 509 participants completed the trial from six centers; 251 were randomized to the intervention group. The mean age was 57 years and 52.3% were female. The primary endpoint was met with an adequacy rate of 216 of 251 (86.1%) in the intervention group, compared with 205 of 259 (79.1%) in the control group ( P <0.05, odds ratio [OR] 1.626, 95% CI 1.017-2.614). The PDR was significantly higher in the intervention group (39% vs 30%, OR 1.51, 95% CI 1.04-2.19, P <0.05). Conclusions An educational video leads to improved bowel preparation for patients attending for their first colonoscopy, and is also associated with greater detection of polyps. Widespread adoption of an educational video incurs minimal investment, but would reduce the number of inadequate procedures, missed pathology, and the cost that both these incur.

Adequate bowel preparation is an important factor in high-quality colonoscopy. It is generally accepted that a Boston Bowel Preparation Scale (BBPS) score ≥ 6 is adequate, but some reports suggest ≥ 7. Subjects who underwent colonoscopy at least twice within 3 years from August 2015 to December 2019 were included. Polyp detection rates (PDRs), adenoma detection rates (ADRs), and number of polyps including adenomas were compared stratified by baseline colonoscopy (C1) BBPS score. Among 2352 subjects, 529 had BBPS 6 (group 1) and 1823 had BBPS 7-9 (group 2) at C1. There was no significant difference in PDR or ADR at C1 and follow-up colonoscopy (C2) between the two groups. However, the numbers of polyps (1.84 vs. 1.56, P = 0.001) and adenomas (1.02 vs. 0.88, P = 0.034) at C2 were significantly higher in group 1 than group 2, respectively. Segmental BBPS score 2 in group 1 compared to group 2, especially, showed higher PDR (P = 0.001) and ADR (P = 0.007) at C2. BBPS 6 is associated with a higher number of polyps and adenomas in short-term follow-up colonoscopy than BBPS 7-9. To reduce the risk of missed polyps, a thorough examination is necessary for BBPS 6.

The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years. Therefore, the population that is ≥ 50 years in age requires long-term and regular colonoscopies. Uncomfortable bowel preparation is the main reason preventing patients from undergoing regular colonoscopies. The standard bowel preparation regimen of 4-L polyethylene glycol (PEG) is effective but poorly tolerated.

To investigate an effective and comfortable bowel preparation regimen for hospitalized patients ≥ 50 years in age.

Patients were randomly assigned to group 1 (2-L PEG + 30-mL lactulose + a low-residue diet) or group 2 (4-L PEG). Adequate bowel preparation was defined as a Boston bowel preparation scale (BBPS) score of ≥ 6, with a score of ≥ 2 for each segment. Non-inferiority was prespecified with a margin of 10%. Additionally, the degree of comfort was assessed based on the comfort questionnaire.

The proportion of patients with a BBPS score of ≥ 6 in group 1 was not significantly different from that in group 2, as demonstrated by intention-to-treat (91.2% vs 91.0%, P = 0.953) and per-protocol (91.8% vs 91.0%, P = 0.802) analyses. Furthermore, in patients ≥ 75 years in age, the proportion of BBPS scores of ≥ 6 in group 1 was not significantly different from that in group 2 (90.9% vs 97.0%, P = 0.716). Group 1 had higher comfort scores (8.85 ± 1.162 vs 7.59 ± 1.735, P < 0.001), longer sleep duration (6.86 ± 1.204 h vs 5.80 ± 1.730 h, P < 0.001), and fewer awakenings (1.42 ± 1.183 vs 2.04 ± 1.835, P = 0.026) than group 2.

For hospitalized patients ≥ 50 years in age, the bowel preparation regimen comprising 2-L PEG + 30-mL lactulose + a low-residue diet produced a cleanse that was as effective as the 4-L PEG regimen and even provided better comfort.

Colorectal cancer (CRC) is the second leading cause of adult cancer-related deaths in the United States. Colonoscopy is the gold standard for CRC screening. Adequate bowel preparation prior to colonoscopy is essential for good visualization, which results in higher polyp detection rates and shorter procedural times. Achieving adequate preparation prior to colonoscopy is accomplished approximately 75% of the time. This review covers current recommendations and recent updates in bowel preparation for colonoscopy.

Split-dose bowel preparation is recommended, but recent studies show that same day, low-volume preparations are noninferior. Low-volume polyethylene glycol with electrolytes + ascorbic acid can achieve high-quality bowel preparation and 1-day, low-residue diets prior to colonoscopy, particularly prepackaged low-residue diets, can lead to better outcomes. Utilizing visual aids and artificial intelligence in the form of smartphone applications and quality prediction systems can also lead to higher rates of bowel preparation adequacy.

An individualized approach should be used to decide on the best preparation option for patients. Lower volume, same day preparations are available and lead to better patient tolerability and compliance, along with less stringent precolonoscopy diets. Smartphone applications and artificial intelligence will allow us to better educate and guide patients with regards to following preparation instructions.

Colonoscopy is widely used as a colorectal cancer (CRC) screening tool. The effectiveness of a screening colonoscopy is associated with a decreased risk of CRC. However, colonoscopy is an operator-dependent procedure, and endoscopists' quality performance varies widely. This article reviewed the priority metrics and practices that contribute to high-quality screening colonoscopy in real-world clinical practice. With growing evidence, quality indicators have been subject to intense research and associated with reducing postcolonoscopy CRC incidence and mortality. Some quality metrics can reflect an endoscopy unit-based practice (i.e. quality of bowel preparation and withdrawal time). Other quality indicators primarily reflect individuals' skill and knowledge (i.e. cecal intubation rate, adenoma detection rate, and appropriately assigned follow-up colonoscopy interval). Measurement and improvement of priority quality indicators for colonoscopy should be made at both the endoscopist and unit levels. Substantial evidence supports the impact of high-quality colonoscopy in reducing the incidence of postcolonoscopy CRC.

The performance of existing image-based training models in evaluating bowel preparation on colonoscopy videos was relatively low, and only a few models used external data to prove their generalization. Therefore, this study attempted to develop a more precise and stable AI system for assessing bowel preparation of colonoscopy video.

We proposed a system named ViENDO to assess the bowel preparation quality, including two CNNs. First, Information-Net was used to identify and filter out colonoscopy video frames unsuitable for Boston bowel preparation scale (BBPS) scoring. Second, BBPS-Net was trained and tested with 5,566 suitable short video clips through three-dimensional (3D) convolutional neural network (CNN) technology to detect BBPS-based insufficient bowel preparation. Then, ViENDO was applied to complete withdrawal colonoscopy videos from multiple centers to predict BBPS segment scores in clinical settings. We also conducted a human-machine contest to compare its performance with endoscopists.

In video clips, BBPS-Net for determining inadequate bowel preparation generated an area under the curve of up to 0.98 and accuracy of 95.2%. When applied to full-length withdrawal colonoscopy videos, ViENDO assessed bowel cleanliness with an accuracy of 93.8% in the internal test set and 91.7% in the external dataset. The human-machine contest demonstrated that the accuracy of ViENDO was slightly superior compared to most endoscopists, though no statistical significance was found.

The 3D-CNN-based AI model showed good performance in evaluating full-length bowel preparation on colonoscopy video. It has the potential as a substitute for endoscopists to provide BBPS-based assessments during daily clinical practice.

Insufficient bowel preparation (BP) presents substantial challenges to the effectiveness of outpatient colonoscopy for colorectal cancer screening, particularly within populations characterized by low health literacy and poor adherence.

We conducted a prospective, randomized, blinded, endoscopic controlled study involving 474 colonoscopy outpatients aged 18-80 years hailing from a low health literacy population with convenient access to WeChat. These patients were subsequently randomized into three groups: the control group, WeChat group, and the automatic reminder group (ARG). All people were administered 3 L of polyethylene glycol. The Boston Bowel Preparation Scale (BBPS) score of 6 or a segmental score of 2 was used as the primary outcome to evaluate BP quality. Secondary outcomes included polyp detection rate (PDR) and adverse events, etc. RESULTS: Our findings revealed that both the WeChat group (n = 158) and ARG (n = 158) exhibited significantly higher rates of adequate BP compared to the control group (n = 158) (WeChat vs. control, 79.1% vs. 61.4%; ARG vs. control, 74.7% vs. 61.4%; p < 0.001). Furthermore, these educationally reinforced groups displayed improved BP compliance (p < 0.05). According to the Hospital Anxiety and Depression Scale (HADS), patients in the reinforced education groups exhibited lower overall anxiety levels (p = 0.001) and experienced fewer adverse reactions (p = 0.019). Compared to the control group, the PDR in the right hemi-colon was significantly greater in the WeChat group (11.4%) (2.5%), and a similar trend was observed in the ARG (7.6%). Additionally, individuals in the WeChat group reported higher levels of satisfaction with their colonoscopy experience (p = 0.043). In a multivariate analysis, adjusting for potential confounding factors, WeChat-based re-education ([OR] 1.496, 95% CI 1.154-1.939; p = 0.002)) emerged as a protective factor for achieving adequate BP.

Enhanced education through WeChat can improve BP quality, and ARG applies equally to low health literacy populations.

In the present prospective case series study, we investigated the lesion-detection ability of an AI-equipped colonoscopy as an addition to colonoscopy (CS) screening. Participants were 100 patients aged ≥20 years who had not undergone CS at the study site in the last 3 years and passed the exclusion criteria. CS procedures were conducted using conventional white light imaging and computer-aided detection (CADe). Adenoma detection rate (ADR; number of individuals with at least one adenoma detected) was compared between the conventional group and the CADe group. Of the 170 lesions identified, the ADR of the CADe group was significantly higher than the ADR of the conventional group (69% vs. 61%, p = 0.008). For the expert endoscopists, although ADR did not differ significantly, the mean number of detected adenomas per procedure (MAP) was significantly higher in the CADe group than in the conventional group (1.7 vs. 1.45, p = 0.034). For non-expert endoscopists, ADR and MAP were significantly higher in the CADe group than in the conventional group (ADR 69.5% vs. 56.6%, p = 0.016; MAP 1.66 vs. 1.11, p < 0.001). These results indicate that the CADe function in CS screening has a positive effect on adenoma detection, especially for non-experts.

Based on published evidence and our expert experience, we provide recommendations to maximize the efficacy, safety, efficiency, and cost-effectiveness of routine colonoscopy. High-quality colonoscopy begins with colon preparation using a split or same-day dose and preferably a low-volume regimen for optimal patient tolerance and compliance. Successful cecal intubation can be achieved by choosing the correct colonoscope and using techniques to facilitate navigation through challenges such as severe angulations and redundant colons. Safety is a primary goal, and complications such as perforation and splenic rupture can be prevented by avoiding pushing through fixed resistance and avoiding loops in proximal colon. Furthermore, barotrauma can be avoided by converting to water filling only (no gas insufflation) in every patient with a narrowed, angulated sigmoid. Optimal polyp detection relies primarily on compulsive attention to inspection as manifested by adequate inspection time, vigorous probing of the spaces between haustral folds, washing and removing residual debris, and achieving full distention. Achieving minimum recommended adenoma detection rate thresholds (30% in men and 20% in women) is mandatory, and colonoscopists should aspire to adenoma detection rate approaching 50% in screening patients. Distal attachments can improve mucosal exposure and increase detection while shortening withdrawal times. Complete resection of polyps complements polyp detection in preventing colorectal cancer. Cold resection is the preferred method for all polyps < 10 mm. For effective cold resection, an adequate rim of normal tissue should be captured in the snare. Finally, cost-effective high-quality colonoscopy requires the procedure not be overused, as demonstrated by following updated United States Multi Society Task Force on Colorectal Cancer postpolypectomy surveillance recommendations.

BACKGROUND : We compared the effectiveness of optional split-dose bowel preparation (SDBP) with mandatory SDBP for morning colonoscopies in usual clinical practice. METHODS : Adult patients undergoing outpatient early morning (8:00 AM-10:30 PM) and late morning (10:30 AM-12:00 PM) colonoscopies were included. Written bowel preparation instructions were provided based on randomization: one group were instructed to take their bowel preparation (4 L polyethylene glycol solution) as a split dose (mandatory), while the comparator group was allowed the choice of SDBP or single-dose bowel preparation administered entirely on the day before (optional). The primary end point, using noninferiority hypothesis testing with a 5 % margin, was adequate bowel cleanliness measured by the Boston Bowel Preparation Scale (BBPS) and defined by a BBPS score ≥ 6. RESULTS : Among 770 randomized patients with complete data, there were 267 mandatory SDBP and 265 optional SDBP patients for early morning colonoscopies, and 120 mandatory SDBP and 118 optional SDBP patients for late morning colonoscopies. Optional SDBP was inferior to mandatory SDBP, with a lower proportion of adequate BBPS cleanliness for early morning colonoscopies (78.9 % vs. 89.9 %; absolute risk difference [aRD] 11.0 %, 95 %CI 5.9 % to 16.1 %), but was not statistically different for late morning colonoscopies (76.3 % vs. 83.3 %; aRD 7.1 %, 95 %CI -1.5 % to 15.5 %). CONCLUSIONS : Optional SDBP is inferior to mandatory SDBP in providing adequate bowel preparation quality for early morning colonoscopies (8:00 AM-10:30 AM), and probably inferior for late morning colonoscopies (10:30 AM-12:00 PM).

Colonoscopy with adenomatous polypectomy reduces the incidence and mortality of colorectal cancer. We introduced a strategy of removing all neoplastic polyps in single-session out-patient colonoscopy using cold polypectomy. We aimed to investigate the achievement of single-session complete removal rate of detected colorectal polyps in clinical practice.

This retrospective study included colonoscopy-scheduled 40-79-year-old outpatients, with at least one colorectal neoplasm, between January 2015 and December 2016. Exclusion criteria were: colorectal neoplasms 21 mm or larger in size; pre-examination for colorectal surgery or endoscopic submucosal dissection; colonoscopy performed by health check program; ongoing antithrombotic treatment; inflammatory bowel disease; familial adenomatous polyposis. We defined 'clean colon' as the removal of all detected neoplastic polyps in a single-session colonoscopy. We evaluated clean colon rate, factors relating to clean colon failure and complications.

We evaluated 2527 patients (mean age 68 years; 799 women) with 8203 colorectal polyps (7675 adenomas, 423 serrated lesions, 105 Tis and T1 cancers). In 1-4 mm polyps, cold snare polypectomy (CSP; 51.8%) and cold forceps polypectomy (CFP; 45.8%) were applied. Clean colon rates were 95.1% per patient and 97.1% per lesion. The significant factors denoting clean colon failure were inadequate bowel preparation, ≥5 lesions, and the most advanced estimated histology of adenocarcinoma, on multivariate analyses. Post-polypectomy bleeding requiring endoscopic hemostasis occurred in five patients (0.2%) who had undergone endoscopic mucosal resection (EMR) or hot snare polypectomy (HSP). Perforation occurred in one patient (0.04%) with EMR.

The clean colon rates were satisfactory in single-session out-patient colonoscopy using cold polypectomy.