The week in GI, filtered to what is worth knowing.

Outpatient positioning is unchanged from the ACG 2025 UC guideline and the AGA living guideline for moderate-to-severe UC. Confirm UC with endoscopy showing continuous colonic inflammation from the rectum plus histology, after excluding infection with two-step C. difficile testing. Treat mild-moderate disease with 5-ASA chosen by route and extent: suppository for proctitis, enema for left-sided disease, oral plus rectal for extensive disease. If 5-ASA fails, treat as moderate-to-severe rather than stepping up gradually. Position advanced therapy by efficacy tier, not by an anti-TNF-first rule. Advanced-therapy-naive, higher efficacy: infliximab, vedolizumab, ozanimod, etrasimod, upadacitinib, risankizumab, guselkumab. Intermediate: golimumab, ustekinumab, tofacitinib, filgotinib, mirikizumab. Lower: adalimumab. Previously TNF-exposed, higher efficacy: tofacitinib, upadacitinib, ustekinumab. Lower: adalimumab, vedolizumab, ozanimod, etrasimod. After anti-TNF primary non-response, switch mechanism rather than cycling within the class. Treat to target (STRIDE-II): endoscopic improvement, Mayo endoscopic subscore 0-1. Begin CRC surveillance 8-10 years after diagnosis for extensive or left-sided disease; isolated proctitis follows average-risk screening. Inpatient care now follows the 2026 AGA Clinical Practice Update (13 best-practice statements). Admit for severe symptoms refractory to outpatient therapy, suspected complications (obstruction, abscess, toxic megacolon) or significant malnutrition, and identify acute severe UC by Truelove-Witts. Give every patient admitted with diarrhea two-step C. difficile testing. Test for CMV, with early endoscopy, if symptoms worsen, the patient is systemically toxic or disease is steroid-refractory. Give routine VTE prophylaxis with LMWH or fondaparinux unless contraindicated, and individualize post-discharge extension. Give IV methylprednisolone 60 mg/day or equivalent; the AGA living guideline says 40-60 mg/day, and higher doses add no benefit. Do not give adjunctive antibiotics without infection. Involve surgery early. Assess response by day 3 (72 h) using stool frequency and CRP (Oxford criteria); do not continue IV steroids beyond about 7 days without response. Rescue steroid non-responders with infliximab (accelerated or intensified dosing in selected patients with high inflammatory burden or protein-losing colopathy), cyclosporine, or a JAK inhibitor at standard or intensified dosing, or with colectomy. Before discharge, the response should be stable and a transition plan should be in place.

In patients with classic GERD symptoms (heartburn, regurgitation) and no alarm symptoms, give an 8-week trial of empiric PPI ONCE DAILY before a meal (strong, moderate evidence); administer PPI 30-60 minutes before a meal rather than at bedtime (strong, moderate). Endoscopy is the FIRST test in patients presenting with dysphagia or other alarm symptoms, the guideline names weight loss and GI bleeding, and also in patients with multiple risk factors for Barrett's esophagus (strong, low). If classic symptoms respond to the 8-week trial, attempt to discontinue the PPI (conditional, low); for patients without erosive esophagitis or Barrett's whose symptoms resolved, an attempt at discontinuation should be made; patients requiring maintenance should take the lowest effective dose. If symptoms do not respond adequately to the 8-week trial, or return on discontinuation, perform diagnostic endoscopy, ideally after PPIs are stopped for 2-4 weeks (strong, low). Where GERD is suspected but unclear and endoscopy shows no objective evidence, perform reflux monitoring OFF therapy to establish the diagnosis (strong, low); conversely, do NOT perform off-therapy reflux monitoring solely as a diagnostic test in patients already known to have LA grade C or D esophagitis or long-segment Barrett's, because the diagnosis is already established (strong, low). In refractory GERD, optimize PPI therapy first (strong, moderate); then pH monitoring OFF PPIs if GERD was not previously established by pH study, long-segment Barrett's, or LA grade C/D esophagitis, versus impedance-pH ON PPIs where GERD is already established but symptoms persist on twice-daily PPI (both conditional, low). Before antireflux surgery or endoscopic therapy, HRM is recommended to rule out achalasia and absent contractility, with provocative testing (e.g., multiple rapid swallows) to identify contractile reserve in ineffective esophageal motility; on-therapy reflux monitoring is suggested before intervention in patients with prior objective GERD findings who remain symptomatic. Antireflux surgery by an experienced surgeon is an option for patients with OBJECTIVE evidence of GERD, with severe esophagitis (LA C/D), large hiatal hernia, or persistent troublesome symptoms benefiting most; TIF is suggested only for troublesome regurgitation or heartburn in patients who do not wish to undergo antireflux surgery and who are WITHOUT severe esophagitis (LA C/D) or hiatal hernia >2 cm. For extraesophageal symptoms WITHOUT typical GERD symptoms, perform reflux testing BEFORE starting PPI therapy (strong, moderate); with concomitant typical symptoms, consider twice-daily PPI for 8-12 weeks before further testing (conditional, low). Lifestyle: weight loss in overweight/obese patients (strong, moderate); avoid meals within 2-3 hours of bedtime, avoid tobacco, avoid trigger foods, and elevate the head of the bed for nighttime symptoms (all conditional, low).

General post-polypectomy surveillance still follows USMSTF 2020 (Gupta et al.), which has not been replaced: 1-2 tubular adenomas <10 mm, 7-10 years; 3-4 tubular adenomas <10 mm, 3-5 years; 5-10 tubular adenomas <10 mm, any adenoma ≥10 mm, or an adenoma with tubulovillous/villous histology or high-grade dysplasia, 3 years; >10 adenomas, 1 year with polyposis evaluation. For serrated polyps: 1-2 SSLs <10 mm, 5-10 years; 3-4 SSLs <10 mm or a hyperplastic polyp ≥10 mm, 3-5 years; an SSL ≥10 mm, an SSL with dysplasia, or a traditional serrated adenoma, 3 years. When findings are mixed, use the shortest interval indicated. Before applying an interval, confirm complete resection and adequate prep. Piecemeal resections get a site check, and malignant (T1) polyps go to a tumor-board pathway. Serrated polyposis syndrome (SPS) is now governed by a separate USMSTF consensus statement (Rex et al., published simultaneously in Gastroenterology, Am J Gastroenterol and GIE on 2026-09-30). It has 11 recommendations. Diagnose SPS with the 2019 WHO criteria, which count the size, cumulative lifetime number and location of serrated polyps. Until SPS is diagnosed, record the number, size and location of serrated polyps in every colonoscopy report. SPS colonoscopy should be done by endoscopists with documented adequate SSL detection, using high-definition white light with or without chromoendoscopy. Without concurrent CRC, endoscopy is preferred over surgery for primary management. If the polyp burden cannot be managed endoscopically, refer to an advanced endoscopic resection expert before surgery. Resect SSLs and hyperplastic polyps by cold snare, with submucosal injection for larger lesions. Do clearance colonoscopy at 3-6 months, then surveil every 1-2 years. Consider 3-year intervals if the burden is greatly reduced at surveillance. First-degree relatives start colonoscopy at age 40, or 10 years before the youngest CRC diagnosis in the family, or 5 years before the youngest SPS diagnosis, whichever comes first. SPS has no established genetic basis, so germline testing is recommended only when concurrent non-serrated polyps suggest a heritable syndrome. Lynch, FAP/AFAP and MAP criteria still trigger genetic evaluation.

Diagnosis: use a positive diagnostic strategy based on Rome IV criteria rather than a strategy of exclusion (strong for cost-effectiveness, high quality; consensus for time-to-therapy), and categorize by IBS subtype (consensus). In patients with IBS and diarrhea symptoms: check celiac serology (strong, moderate) and, in those WITHOUT alarm features, fecal calprotectin (or fecal lactoferrin) plus CRP to rule out IBD (strong; moderate quality for CRP/calprotectin, very low for lactoferrin). Recommend AGAINST routine stool testing for enteric pathogens (conditional, low) and AGAINST routine colonoscopy in patients younger than 45 without warning signs (conditional, low). Anorectal physiology testing only when symptoms suggest a pelvic floor disorder and/or for refractory constipation not responding to standard medical therapy (consensus). Treatment, all subtypes: soluble, not insoluble, fiber (strong, moderate); a LIMITED trial of a low-FODMAP diet (conditional, very low); gut-directed psychotherapies for global symptoms (conditional, very low); TCAs for global symptoms (strong, moderate); peppermint suggested (conditional, low); antispasmodics for abdominal pain (conditional, low); AGAINST probiotics (conditional, very low), AGAINST fecal transplant (strong, very low). IBS-C: chloride channel activators (strong, moderate) and guanylate cyclase activators (strong, high); AGAINST PEG products for global IBS-C symptoms (conditional, low); tegaserod reserved for women younger than 65 with ≤1 cardiovascular risk factor who have not adequately responded to secretagogues (strong/conditional, low). IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

U.S. Multi-Society Task Force (2017 guideline, revised by the 2022 focused update on age to start and stop): offer average-risk colorectal cancer screening to everyone aged 45-75. Screening at 45-49 is a weaker recommendation than at 50-75. Colonoscopy every 10 years and annual FIT are the Tier 1 cornerstones. Tier 2 alternatives are multi-target stool DNA every 3 years, CT colonography every 5 years, and flexible sigmoidoscopy every 5-10 years. Capsule colonoscopy every 5 years is Tier 3. Any abnormal non-colonoscopy test requires a diagnostic colonoscopy, and a stool test should not be offered to a patient who would decline follow-up colonoscopy. Patients who are up to date with negative prior screening, particularly a high-quality colonoscopy, may consider stopping at 75 or when life expectancy is under 10 years. Decisions at 76-85 are individualized by health and prior screening, and screening after 85 is not recommended. The American Cancer Society's May 2026 guideline agrees on the 45-75 range, no screening after 85, and colonoscopy as the preferred option. It adds the next-generation mt-sDNA test and the multitarget stool RNA test (ColoSense), both every 3 years, and it adds an FDA-approved blood-based cfDNA test (Shield) only for people who decline or do not complete visual or stool screening. ACS says a positive stool or blood test should be followed by colonoscopy, preferably within 6 months. The 2026 ASGE paper on follow-up after an abnormal stool test is an implementation review (navigation, tracking, direct-access colonoscopy), not a new screening guideline.