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.

Background: Polyethylene glycol (PEG) has been regarded as the primary recommendation for bowel preparation before colonoscopy. However, a conclusive conclusion has not yet been generated. Aim: We performed this updated meta-analysis to further investigate the comparative efficacy and safety of low volume preparation based on PEG plus ascorbic acid related to 4L PEG. Methods: A systematic search was conducted to retrieve potential randomized controlled trials (RCTs) in PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) from January 2000 to April 2018. Two independent searchers critically searched all potential citations, extracted data, and appraised risk of bias accordingly. Moreover, we used the STATA 12.0 and trial sequential analysis (TSA) 0.9 to complete all analyses. Results: A total of 13 RCTs enrolling 3,910 patients met inclusion criteria. Meta-analysis based on PP analysis indicated that compared to standard volume PEG regime, low volume regime improved patient compliance RR = 1.01; 95% CIs = 1.00, 1.03; P = 0.143 (≥75% intake); RR = 1.07; 95% CIs = 1.00, 1.14; P = 0.046 (100% intake), the willingness to repeat the same regime (RR = 1.30; 95% CIs = 1.07, 157; P = 0.007), and patient acceptability (RR = 1.18; 95% CIs = 1.07, 1.29; P = 0.001), and decreased the overall adverse events (RR = 0.86; 95% CIs = 0.77, 0.96; P = 0.009). However, no difference was observed between these two different solutions for bowel preparation efficacy (RR = 0.98; 95% CIs = 0.95, 1.02; P = 0.340). These all results were further confirmed by TSA. Conclusions: The effect of low volume regime was not inferior to the standard volume PEG regime, and low volume regime was associated with better compliance when subjects ingested all the solution, willingness to repeat the same regime, higher acceptability, and lower nausea in non-selected population.

Objective: We tested the hypothesis that an enhanced bowel preparation strategy (EBS) improves colonic cleansing in patients at high risk for inadequate bowel cleansing (HRI). Methods: This prospective randomized clinical trial included consecutive HRI patients referred for outpatient colonoscopy between February and October 2019. HRI was considered if patients scored >1.225 according to a previously validated bowel-cleansing predictive score. HRI patients were randomized (1:1) to a low-volume conventional bowel cleansing strategy (CBS) (1-day low residue diet (LRD) plus 2 L of polyethylene glycol (PEG) plus ascorbic acid) or to an EBS (3-day LRD plus 10 mg oral bisacodyl plus 4 L PEG). The Boston Bowel Preparation Scale (BBPS) was used to assess the quality of cleanliness. Intention-to-treat (ITT) and per protocol (PP) analyses were performed. A sample size of 130 patients per group was estimated to reach a 15% difference in favor of EBP. Results: A total of 253 HRI patients were included (mean age 69.8 ± 9.5 years, 51.8% women). No statistically significant differences were found in the BBPS scale between the two groups in the ITT analysis (CBS 76.8% vs. EBS 79.7%, P = 0.58) or PP analysis (CBS 78% vs. EBS 84.3%, P = 0.21), risk difference 2.9% (95% CI-7.26 to 39.16) in the ITT analysis, or risk difference 6.3% (95% CI-3.48 to 16.08) in PP analysis. No differences in preparation tolerance, compliance, adverse effects, or colonoscopy findings were found. Conclusion: EBS is not superior to CBS in hard-to-prepare patients. (EUDRACT: 2017-000787-15, NCT03830489). Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03830489.

Background: Castor oil (CaO) has the potential of halving the required volume of bowel preparation solution; however, no clinical trial investigated the efficacy of CaO on bowel preparation for colonoscopy in addition to polyethylene glycol (PEG). Objectives: Our aim was to evaluate efficacy and safety of lower dose PEG together with 30 mL CaO alone or plus ascorbic acid (Asc) in bowel preparation before colonoscopy. Methods: Two hundred and forty-six patients were allocated randomly to ingest 2 L PEG with 30 mL CaO, 1 L PEG with 30 mL CaO plus 5 g Asc, or 3 L PEG. We used Boston Bowel Preparation Scale (BBPS) to evaluate bowel preparation efficacy. We also determined other outcomes such as procedure time, polyp or adenoma detection rate, and adverse events (AEs). Results: Of 282 patients recruited, 36 were excluded. Groups were matched for baseline characteristics except weight (P = 0.020) and body mass index (BMI) (P = 0.003). Patient's satisfaction was higher in 2 L PEG-CaO (P = 0.016) and 1 L PEG-CaO-Asc groups (P = 0·017). Patients' compliance was 67.5, 71.4, and 80.5% in 3 L PEG, 2 L PEG-CaO, and 1 L PEG-CaO-Asc groups (P = 0.014). Adequate bowel preparation rate was 75, 78.57, and 53.66% in 3 L PEG, 2 L PEG-CaO, and 1 L PEG-CaO-Asc groups (P = 0.021). There were no differences in terms of remaining outcomes. Conclusions: Despite an increase in patients' satisfaction and compliance, 1 L PEG-CaO-Asc significantly decreased adequate bowel preparation rate. However, 2 L PEG-CaO improved the patients' satisfaction and compliance and increased adequate bowel preparation rate (Registration number, ChiCTR-IIR-17012418).

Introduction: The fecal immunochemical test (FIT) has been established as a cost-effective test in colon cancer screening programmes. This test could also be helpful in symptomatic patients prior to colonoscopy, but data about diagnostic performance, and accurate cut-off values for these patients are still scarce. Materials and Methods: Prospective study that included consecutive unselected patients with gastrointestinal symptoms referred for colonoscopy between November 2016 and June 2018. We performed a FIT (FOB Gold® test, cut-off 20 micrograms of Hb/gram of feces) prior to colonoscopy and determined the accuracy of FIT in terms of sensitivity, specificity, positive and negative predictive value for clinically significant pathology, advanced neoplasia, and colorectal cancer in symptomatic patients, using two different cut-off values. Results: A total of 727 patients (44.3% men, aged 58.5 ± 14.9 years) was included in the study. The main symptom was history of previous (non-active) rectal bleeding (34.7%), followed by diarrhea (15.0%). Over one quarter of the patients (25.9%) had a positive FIT result. The caecal intubation rate was 95.5%. Clinically significant pathology was identified in 142 colonoscopies (19.5%), advanced neoplasia in 115 (15.8%) and colorectal cancer in 36 colonoscopies (5.0%). FIT performed very well for clinically significant pathology, advanced neoplasia and cancer, with a high negative predictive value (NPV). Reducing the cut-off value to 10 μg/g yielded similar NPV results, with a decrease in specificity. Using a combination of symptoms with a positive FIT result did not improve FIT performance. Only specificity was slightly higher compared to FIT alone, but this was paralleled by a decrease in sensitivity and NPV for cancer and clinically significant pathology. The odds of presenting clinically significant pathology, advanced neoplasia, or cancer increased with FIT concentration. Conclusions: The specificity and NPV of FIT for clinically significant pathology, advanced neoplasia, and cancer are high in symptomatic patients. FIT is a helpful test for determining the need to perform further studies. It may not be necessary to reduce the cut-off value for symptomatic patients, since FIT performance with the current standard cut-off value used in colorectal cancer screening was accurate. FIT can be used to avoid or prioritize colonoscopy procedures.

Background: Bowel preparation is necessary for successful colonoscopy, while it can seriously affect intestinal microbial composition and damage the intestinal mucosal barriers in humans. Methods: To figure out whether probiotics can sustain intestinal homeostasis and guard people's health, the probiotic drug of Bifidobacterium Tetragenous viable Bacteria Tablets (P group, n = 16) or placebo (C group, n = 16) was used for volunteers receiving bowel preparation, and high-throughput sequencing method was applied to monitor their intestinal microbial changes. Results: The present results suggested that bowel preparation obviously reduced the intestinal microbial diversity, while taking probiotics significantly restored it to normal level. In addition, probiotics sharply reduced the abundance of pathogenic Proteobacteria, and obviously lowered the ratio of Firmicutes/Bacteroidetes compared with control group at phylum level (P < 0.05). And probiotics markedly decreased the abundance of pathogenic Acinetobacter and Streptococcus, while greatly enriched the relative abundance of beneficial bacteria Bacteroides, Roseburia, Faecalibacterium, and Parabacteroides at genus level (P < 0.05). Conclusion: Probiotic drugs, e.g., Bifidobacterium Tetragenous viable Bacteria Tablets, can be used to restore intestinal dysbacteriosis caused by bowel preparation, and reduce side effects during colonoscopy.

Background: Diversion colitis is a non-specific inflammation of a defunctionalised segment of the colon after a temporary stoma has been performed. This inflammation is associated with a change in the colonic flora. Aim: To evaluate the efficacy and safety of preoperative stimulation of the efferent loop with probiotics prior to closure of the protective ileostomy in patients operated on colorectal carcinoma and its effect on diversion colitis. A prospective, randomised, double-blind, controlled study is carried out. Methods: Patients who underwent surgery for colorectal carcinoma with protective ileostomy pending reconstructive surgery and with diversion colitis as diagnosis are included. Randomised and divided into two groups. Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery. Results: Patients in CG were distributed according to the endoscopic index of severity in pre-stimulation/post-stimulation as follows: severe n = 9/9 (25.7%), moderate n = 23/23 (65.7%), and mild n = 3/3 (8.6%); compared to the distribution in SG, severe n = 9/0 (26.5/0%), moderate n = 23/3 (67.6/8.8%), mild n = 2/19 (5.9/55.9%) and normal colonoscopy in 0/12 patients (0/35.3%). Conclusion: Probiotic stimulation of the efferent loop is a safe and effective method, managing to reduce both macroscopic and microscopic colitis, as well as a decrease in symptoms in the short term after reconstructive surgery.

Difficulty in providing endoscopy for patients with iron deficiency anaemia (IDA) during the COVID-19 pandemic has highlighted the requirement for a prioritisation tool. We aimed to test the validity of qFIT as a prioritisation tool in patients with iron deficiency and its ability to identify patients with advanced neoplastic lesions (ANLs). Data collected from patients referred with biochemically proven iron deficiency (ferritin ≤ 15 μg/L) and synchronous qFIT who underwent full gastrointestinal investigation within NHS Greater Glasgow and Clyde was analysed retrospectively. Patients who did not undergo full investigation, defined as gastroscopy and colonoscopy or CT colonography, were excluded. ANLs were defined as defined as upper GI cancer, colorectal adenoma ≥ 1 cm or colorectal cancer. Area under the curve (AUC) analysis was performed on qFIT results and outcome, defined as the presence of an ANL. AUC analysis guided cut-off scores for qFIT. Patients with a qFIT of <10, 10-200, >200, were allocated a score of 1, 2, and 3, respectively. A total of 575 patients met criteria for inclusion into the study. Overall, qFIT results strongly predicted the presence of ANLs (AUC 0.87, CI 0.81-0.92; P < 0.001). The prevalence of ANLs in patients with scores 1-3 was 1.2, 13.5, and 38.9% respectfully. When controlled for other significant variables, patients with a higher qFIT score were statistically more likely to have an ANL (qFIT score = 2; OR 12.8; P < 0.001, qFIT score = 3, OR 50.0; P < 0.001). A negative qFIT had a high NPV for the presence of ANLs (98.8%, CI 97.0-99.5%). These results strongly suggest that qFIT has validity as a prioritisation tool in patients with iron deficiency; both allowing for a more informed decision of investigation of patients with very low risk of malignancy, and in identifying higher risk patients who may benefit from more urgent endoscopy.

Background: Screening with fecal occult blood test reduces colorectal cancer (CRC) incidence and mortality, and is currently implemented in most countries. However, around 40% of screening colonoscopies are normal. Thus, strategies to avoid these colonoscopies are highly necessary. Adding other fecal biomarkers, such as fecal calprotectin (FC), lactoferrin, and transferrin may be useful, but evidence is scarce. Aims: To evaluate the diagnostic accuracy of fecal occult blood immunochemical test (FIT), FC, and a one-step combo card test for the simultaneous semi-qualitative detection of human hemoglobin (hHb), transferrin (hTf), calprotectin (hCp) and lactoferrin (hLf) in a CRC screening program population. Methods: Single-center, prospective observational study, enrolling patients included in a CRC screening program, referred for a colonoscopy due to a positive FIT test. Participants collected a stool sample prior to bowel preparation, and FIT, FC and the combo semi-qualitative tests were performed on the sample. Sensitivity, specificity, positive and negative predictive values and area under receiver operator curve (AUC) for diagnosis of advanced neoplasia, advanced adenoma and CRC were estimated for each biomarker and their combinations. The primary endpoint of the study was to assess whether these biomarkers could improve the diagnostic accuracy of FIT alone. Results: 336 consecutive patients (64% males) were recruited. Advanced neoplasia was found in 129/336 (38.4%) patients, and of these, 22/336 (6.5%) were diagnosed of CRC. 153/336 (45.5%) colonoscopies were completely normal. The AUC for the diagnosis of advanced neoplasia were 0.725 (95%CI 0.665-0.784) for FIT, 0.477 (95%CI 0.413-0.541) for FC and 0.732 (95%CI 0.674-0.791) for the combination of both (FIT + FC) quantitative tests. The AUCs for the combo test were 0.70 (95%CI 0.641-0.760) for hHb, 0.625 (95%CI 0.562-0.698) for hTf, 0.532 (95%CI 0.469-0.595) for hCp, 0.531 (95%CI 0.466-0.595 ) for hLf and 0.681 (95%CI 0.620-0.741) for the combination of the four biomarkers. Conclusion: In average-risk population, FIT appears to be the best fecal marker for the diagnosis of CRC and advanced adenoma. None of the other biomarkers explored or their combinations provided a better diagnostic accuracy. Only hTF showed an acceptable diagnostic accuracy. FC and hLF were not useful in this setting.