Gaurav Bhaskar Nigam

Background: Over half of patients with Crohn’s disease (CD) develop intestinal strictures that often require surgical resection. Endoscopic balloon dilatation (EBD) can be a potential alternative therapeutic option. Methods: This retrospective cohort study included adult patients with CD (≥18 years) who underwent EBD between January 2016 and September 2024 at two Canadian hospitals. The primary outcome was technical success. Secondary outcomes were clinical success at 6 and 12 months, hospitalization due to obstruction, and CD-related surgery. Cox proportional hazards models assessed predictors of outcomes. Results: A total of 234 patients (age: 47.6 years, males: 47.4%) were included with mean disease duration of 17.7 years and median follow-up of 61 months. A majority of the strictures (226/234) were dilated under ileocolonoscopy guidance, and 79.4% had symptoms at baseline. Most strictures were of de novo type (62.5%) and the median number of stricture dilatations was 3 (IQR: 2). Technical success was achieved in 81% (150/185). Clinical success was noted in 47.7% at 6 months. The cumulative probabilities of being hospitalization-free were 96.9% (95% CI 94.7-99.2]) at 1 year, 91.3% (95% CI 87.5-95.2) at 3 years, and 85.0% (95% CI 79.8-90.5) at 5 years. The cumulative probabilities of being surgery-free were 91.1% (95% CI 87.5-94.9) at 1 year, 81.7% (95% CI 76.5-87.2) at 3 years, and 78.1% (95% CI 72.4-84.3) at 5 years. Multiple strictures were associated with an increased risk of surgery while anastomotic strictures and maximum balloon diameter were associated with lower risk. No patients experienced procedure-related complications. Conclusions: EBD is effective and safe in de novo and anastomotic strictures with the majority of patients achieving technical success and being free of surgery within 5 years.

Acute upper gastrointestinal bleeding (AUGIB) is a common medical emergency with estimated one admission every 6 min and an annual incidence of 134 per hundred thousand people in the UK.1 It remains associated with substantial morbidity, mortality and healthcare costs, with contemporary UK data reporting an in-hospital mortality of 8.8%. 2Endoscopic intervention is central to management of AUGIB, providing both diagnostic clarity and definitive haemostatic therapy.3 Timely and effective endoscopic haemostasis reduces ongoing bleeding, rebleeding risk and the need for escalation to surgery or radiological interventions along with appropriate supportive care and pharmacological therapies.4 Modern endoscopic haemostasis encompasses a broad and increasingly complex range of techniques, including injection therapy, thermal coagulation, mechanical methods such as through-the-scope clips and over-the-scope clips and topical haemostatic agents.4 While these advances have improved outcomes in selected high-risk bleeding scenarios, they have also increased the technical and cognitive demands placed on endoscopists, requiring rapid decision-making, device familiarity and procedural competence in high-pressure emergency settings. However, evidence from the UK and international surveys consistently demonstrates significant variability in training exposure and confidence in AUGIB management among gastroenterology trainees.5–7 Compared with diagnostic upper gastrointestinal endoscopy, hands-on experience with haemostatic techniques is limited particularly for advanced or less frequently used interventions. As a result, many trainees report low confidence in managing AUGIB independently at the point of completion of training.5 8 These gaps are compounded by service pressures, exclusion from bleeding rotas and limited access to structured haemostasis training. The gaps are also due to a shortening of the training programme duration through Shape of Training. Professional bodies including the British Society of Gastroenterology (BSG) and the European Society of Gastroenterological Endoscopy advocate competency-based approaches to endoscopy training, emphasising structured curricula, objective assessment and the use of simulation to support skill acquisition.9 Simulation-based training has been shown to improve technical performance and decision-making in haemostasis while minimising patient risk.10 Nevertheless, access to simulation facilities, formalised curricula and standardised haemostasis courses remains inconsistent, and there is currently no agreed national or international framework defining the essential components of AUGIB haemostasis training.

Non-ampullary duodenal adenomas (NADAs) are increasingly recognised because of improvements in endoscopy quality and the rising number of procedures performed. NADAs are premalignant lesions that follow an adenoma–carcinoma sequence; therefore, endoscopic resection is usually recommended. However, decision-making regarding endoscopic resection remains complex because of the challenging duodenal anatomy, evolving resection technologies and the high risk of complications in this location. This review aims to provide a comprehensive, evidence-based synthesis of current knowledge regarding the management of NADAs. We examine epidemiology, natural history, endoscopic assessment techniques, indications for intervention, resection techniques, adverse event management, outcomes and recurrence patterns. High-quality evidence remains limited because of the relative rarity of these lesions. Although several classification systems for endoscopic characterisation have been developed for colorectal polyps, corresponding classifications for NADAs remain less well developed and are not widely embedded in routine practice. Cold snare resection techniques are well established for small NADAs, while emerging evidence supports the expanding role of cold endoscopic mucosal resection (EMR) for selected intermediate-sized lesions because of its favourable safety profile. Hot EMR remains an established and widely available approach for larger or more complex lesions. Experience with endoscopic submucosal dissection is increasing, although it is generally reserved for selected NADAs in which en bloc R0 resection is required, particularly lesions with suspected focal high-grade dysplasia or invasion and should be performed in high-volume expert centres because of its substantial procedural risk. Complications in the duodenum can have devastating consequences compared with other areas of the gastrointestinal tract. A tailored approach balancing safety, oncological outcomes, operator experience and healthcare resources is therefore advised.

Patients with inflammatory bowel disease (IBD) frequently undergo colonoscopy, each requiring bowel preparation. European Society of Gastrointestinal Endoscopy (ESGE) 2019 guidelines recommended high- or low-volume polyethylene glycol (PEG)-based bowel prep for IBD patients; however other non-PEG-based preparations (sulphate and picosulphate-based) have now been studied in IBD. We searched CENTRAL, ClinicalTrials.gov, Embase, MEDLINE, and the World Health Organization International Clinical Trials Registry Platform for randomized controlled trials (RCTs) up to December 2024. Primary outcome was bowel prep success; secondary outcomes included tolerability, acceptability, cecal intubation rates (CIR) and safety. Pooled estimates used risk ratio (RR) and GRADE to assess evidence certainty. Ten RCTs (1479 IBD patients) were included. There was no difference in prep success (relative risk [RR] 0.98, 95% confidence interval [CI] 0.88–1.09; I2 = 33%, 2 RCTs; moderate certainty evidence) between 2 L vs. 4 L PEG, but higher acceptability for 2 L (RR 0.69, 95% CI 0.59–0.80; I2 = 18%, 2 RCTs; high certainty evidence). Low-volume non-PEG vs. PEG are probably similar for prep success (RR 0.96, 95% CI 0.90–1.01; I2 = 6%,3 RCTs; moderate certainty evidence). The evidence on tolerability and acceptability was very uncertain. Subgroup analysis revealed comparable effectiveness of picosulphate-based (RR 0.89, 95% CI 0.78–1.01; I2 = 0%,1 RCT) and sulphate-based preps (RR 0.98, 95% CI 0.91–1.05; I2 = 28%, 2 RCTs) compared with low-volume PEG. Safety data were inconsistently reported. High-certainty evidence supports low-volume PEG as comparably successful to high-volume PEG, with higher acceptability. Moderate-certainty evidence indicates similar success between non-PEG and PEG-based preps. Both low-volume PEG and non-PEG-based preps are supported for use in IBD, broadening options beyond current ESGE guidelines.

This comprehensive review of Sphingosine-1-phosphate receptor modulators explores their mechanism of action, key clinical trial data, real-world insights, and an overview of their safety, including considerations for special populations and comparative effectiveness.

Objective: The incidence of colorectal cancer (CRC) remains elevated in the inflammatory bowel disease (IBD) population. We aimed to examine the association of biologics, 5-aminosalicylates (5-ASAs) and immunomodulators with the risk of CRC and/or dysplasia (CRC/Dys) in different IBD phenotypes. Methods: We searched Web of Science, PubMed, MEDLINE and EMBASE from inception to 15 March 2025 for all studies assessing the association of biologics, 5-ASAs and immunomodulators on the occurrence of CRC/Dys in adults (≥16 years) with IBD. No randomised controlled trials were identified. Data were pooled using a random effects model generating relative risk (RR) estimates. Results: Fifty observational studies containing 29 325 cases of CRC/Dys in 1 434 939 patients with IBD were included. Biologic therapies (RR 0.74; 95% CI 0.64 to 0.85, I ² =56.8%) and 5-ASAs (RR 0.78; 95% CI 0.70 to 0.86, I ² =52.1%) were associated with a reduced risk of CRC/Dys in patients with IBD. Immunomodulators were not associated with a reduced risk (RR 0.92; 95% CI 0.82 to 1.02, I ² =82.7%). After stratification for IBD phenotypes, medication subgroups and CRC outcome, anti-tumour necrosis factor (anti-TNF) therapies were associated with a reduced risk of CRC in patients with ulcerative colitis (RR 0.78; 95% CI 0.73 to 0.83, I ² =0%) but not in Crohn’s disease. Non-sulfasalazine 5-ASAs were associated with a reduced risk of CRC in ulcerative colitis (RR 0.66; 95% CI 0.45 to 0.96, I ² =75.4%) and Crohn’s disease (RR 0.84; 95% CI 0.81 to 0.87, I ² =41.9%). Conclusion: Use of anti-TNF biologics or non-sulfasalazine 5-ASAs is associated with a reduction in CRC risk in IBD, with differential effects by IBD phenotype. PROSPERO registration number: CRD42024559501.

Background Acute upper gastrointestinal bleeding (AUGIB) is a common medical emergency with evolving demographics and management strategies, particularly in medical/endoscopic therapy and transfusion strategies. Objective To provide key data of the most recent 2022 UK audit and compare it with the preceding audit in 2007. Design Prospective multicentre audit conducted from 3 May to 2 July 2022, including adults (≥16 years) with AUGIB across 147 UK hospitals (response rate 86% vs 84% in 2007). AUGIB was defined by clinical symptoms (haematemesis, haematochezia, coffee ground vomiting or melaena confirmed by medical personnel). Patients were followed until discharge, death or 28 days, with re-admissions during the study period counted as new episodes. Results Among 5141 patients (59% male; median age 69), 15% had cirrhosis, 19% reported excess alcohol use, 7% used non-steroidal anti-inflammatory drugs (NSAIDs) and 46% were on antithrombotics. Most (77%) were new admissions, who were younger with fewer comorbidities, while the remainder bled during hospitalisation. Peptic ulcer disease accounted for 32% of cases, varices for 10% and no abnormality was found in 33%. Pre-endoscopic risk stratification was not performed in 42%. Compared with 2007, patients in 2022 had higher comorbidity (67% vs 50%), more cirrhosis (15% vs 9%), greater anticoagulant use (31% vs 13%) and higher transfusion rates (50% vs 43%). In 2022, among early transfusions (pre-endoscopy or within first 24 hrs; 38%), 43% were given at haemoglobin (Hb)>70 g/L, with 24% classified as inappropriate due to haemodynamic stability. A signal of harm was observed: while inappropriate transfusion was not associated with rebleeding at either 70 or 80 g/L, at 80 g/L it was linked to higher adjusted mortality (adjusted OR (aOR) 1.60, 95% CI 1.00 to 2.56). Inpatient endoscopy was more common (83% vs 74%), though endotherapy use remained modest (27% vs 23%). Salvage therapy rates were unchanged (3.3% vs 3.1%) but shifted from surgery to interventional radiology. Outcomes improved, with lower rebleeding (9.7% vs 13.3%), reduced in-hospital mortality (8.8% vs 10.0%) and shorter median stay (5 vs 6 days). In multivariate analysis, mortality was independently predicted by older age (≥80 years: aOR 2.32, 95% CI 1.64 to 3.30), shock (aOR 2.22, 95% CI 1.53 to 3.17) and comorbidity, while lower Hb at presentation increased risk (≤70 g/L: aOR 1.56, 95% CI 1.15 to 2.11). Anticoagulant use was associated with increased mortality (aOR 1.43, 95% CI 1.11 to 1.85), whereas NSAID use (aOR 0.49, 95% CI 0.25 to 0.96) and antiplatelet use (aOR 0.68, 95% CI 0.54 to 0.87) were associated with lower mortality. Conclusions Despite a higher-risk case mix and incomplete adherence to guidelines (notably in transfusion thresholds and risk stratification), outcomes in AUGIB have improved. The observation of increased mortality with liberal transfusion above 80 g/L in stable patients reinforces the importance of restrictive transfusion practice. Quality improvement initiatives focused on risk stratification, endoscopic training and multidisciplinary care could further enhance outcomes in the UK and internationally.

While machine learning algorithms hold promise for personalised medicine, their clinical adoption remains limited, partly due to biases that can compromise the reliability of predictions. In this article, we focus on sample selection bias (SSB), a specific type of bias where the study population is less representative of the target population, leading to biased and potentially harmful decisions. Despite being well-known in the literature, SSB remains scarcely studied in machine learning for healthcare. Moreover, the existing machine learning techniques try to correct the bias mostly by balancing distributions between the study and the target populations, which may result in a loss of predictive performance. To address these problems, our study illustrates the potential risks associated with SSB by examining SSB’s impact on the performance of machine learning algorithms. Most importantly, we propose a new research direction for addressing SSB, based on the target population identification rather than the bias correction. Specifically, we propose two independent networks (T-Net) and a multitasking network (MT-Net) for addressing SSB, where one network/task identifies the target subpopulation which is representative of the study population and the second makes predictions for the identified subpopulation. Our empirical results with synthetic and semi-synthetic datasets highlight that SSB can lead to a large drop in the performance of an algorithm for the target population as compared with the study population, as well as a substantial difference in the performance for the target subpopulations that are representative of the selected and the non-selected patients from the study population. Furthermore, our proposed techniques demonstrate robustness across various settings, including different dataset sizes, event rates and selection rates, outperforming the existing bias correction techniques.

Patients with inflammatory bowel disease (IBD) remain at increased risk for colorectal cancer and death from colorectal cancer compared with the general population despite improvements in inflammation control with advanced therapies, colonoscopic surveillance and reductions in environmental risk factors. This guideline update from 2010 for colorectal surveillance of patients over 16 years with colonic inflammatory bowel disease was developed by stakeholders representing UK physicians, endoscopists, surgeons, specialist nurses and patients with GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodological support. An a priori protocol was published describing the approach to three levels of statement: GRADE recommendations, good practice statements or expert opinion statements. A systematic review of 7599 publications, with appraisal and GRADE analysis of trials and network meta-analysis, where appropriate, was performed. Risk thresholding guided GRADE judgements. We made 73 statements for the delivery of an IBD colorectal surveillance service, including outcome standards for service and endoscopist audit, and the importance of shared decision-making with patients. Core areas include: risk of colorectal cancer, IBD-related post-colonoscopy colorectal cancer; service organisation and supporting patient concordance; starting and stopping surveillance, who should or should not receive surveillance; risk stratification, including web-based multivariate risk calculation of surveillance intervals; colonoscopic modalities, bowel preparation, biomarkers and artificial intelligence aided detection; chemoprevention; the role of non-conventional dysplasia, serrated lesions and non-targeted biopsies; management of dysplasia, both endoscopic and surgical, and the structure and role of the multidisciplinary team in IBD dysplasia management; training in IBD colonoscopic surveillance, sustainability (green endoscopy), cost-effectiveness and patient experience. Sixteen research priorities are suggested.