Motility, in full.

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).

Two 2026 AGA expert reviews now take precedence over the ACG 2021 guideline on several points. They are the AGA Clinical Practice Update on CDI in adults (Clin Gastroenterol Hepatol 2026; 14 best practice advice statements) and the AGA update on CDI in IBD (Gastroenterology 2026; 12 statements). Neither grades its statements with GRADE. DIAGNOSIS: CDI is a clinical diagnosis that needs compatible symptoms (about 3 or more unformed stools in 24 h) plus supportive lab testing. A multistep algorithm is preferred: a sensitive test (GDH or NAAT), then toxin EIA. A NAAT+/EIA- result should be read with caution, and patients with discordant results but high clinical suspicion should still be treated. SEVERITY: classify hospitalized patients at diagnosis. Severe is WBC >15,000/µL and/or creatinine >1.5 (ACG: >1.5 mg/dL; one secondary summary of the AGA text reports >1.5 times baseline). Fulminant is shock, ileus, or megacolon. INITIAL NONFULMINANT EPISODE (nonsevere or severe): fidaxomicin 200 mg twice daily for 10 days is favored first-line because of its narrower spectrum and lower recurrence. Oral vancomycin 125 mg four times daily for 10 days is an acceptable alternative. Metronidazole should not be used outside fulminant disease, which removes the ACG 2021 low-risk metronidazole option. Do not use cholestyramine or other bile-acid binders as monotherapy or alongside vancomycin or fidaxomicin. FULMINANT: manage with a multidisciplinary team. Give oral or enteral vancomycin 500 mg every 6 hours plus IV metronidazole 500 mg every 8 hours, and add rectal vancomycin 500 mg every 6 hours if ileus is present. Consider multi-dose FMT by lower endoscopy. The licensed products (fecal microbiota, live-jslm; fecal microbiota spores, live-brpk) are not approved for severe or fulminant CDI. After severe or fulminant CDI, keep the patient on suppressive vancomycin until a final outpatient FMT. FIRST RECURRENCE (within 8 weeks of finishing therapy): tapering/pulsed vancomycin or fidaxomicin, plus a recurrence-risk assessment and consideration of microbiota restoration. MICROBIOTA-BASED THERAPY (FMT or the licensed products): offer after treatment of a second recurrence. Consider it after an initial episode or first recurrence in patients at high risk of further recurrence or with a severe or refractory episode. SUPPRESSION: consider prolonged low-dose vancomycin 125 mg daily for patients with multiple recurrences who cannot receive or have failed microbiota-based therapy, have limited life expectancy or ongoing comorbidities, or need frequent systemic antibiotics. PREVENTION: do not use vancomycin prophylaxis during systemic antibiotics in the general population. Do not use probiotics for primary or secondary prevention. Encourage a high-fiber diet. Do not stop a PPI that has a legitimate indication, but review its use. Counsel patients with prior CDI to avoid unnecessary antibiotics. Use barrier precautions and EPA-approved sporicidal disinfection. No routine test of cure: retest only for persistent or worsening diarrhea. Bezlotoxumab does not appear in the AGA statements (Merck discontinued it in January 2025). IBD (AGA 2026): test for CDI in IBD patients with new or worsening diarrhea, including those with a pouch or ileostomy, using a multistep toxin-based assay. Treat a first episode preferentially with fidaxomicin, or vancomycin if fidaxomicin is unavailable or too costly. Never use metronidazole. Continue necessary IBD immunosuppression during CDI, and steroids may be used if needed. If symptoms persist after 48-72 h of treatment, consider endoscopy to assess IBD activity and CMV. Offer microbiome-based therapy after at least one recurrence. No probiotics. Oral vancomycin prophylaxis may be considered during systemic antibiotics in IBD patients with prior CDI. The summaries reviewed did not mention the ACG 14-day minimum vancomycin course in IBD.

First exclude emergency/secondary causes (cauda equina/cord compression, fecal impaction with overflow) with a mandatory digital rectal exam, screen for eating disorder before dietary restriction, and classify the subtype (urge, passive, overflow, mixed) since it drives therapy. Work up loose-stool FI for inflammatory, infectious, and bile-acid drivers before labeling idiopathic. Manage with a stepwise ladder: optimize stool consistency (fiber, loperamide, bile-acid sequestrant, or TCA neuromodulator), pelvic floor PT plus biofeedback, skin protection and bridge devices, then escalate to surgical therapy. Prescribe the antimotility/neuromodulator agents with their indications, dosing, and safety limits: loperamide is first-line for loose-stool/urge FI, start low (e.g., 2 mg before meals or as needed) and titrate to stool consistency while staying within the FDA-approved maximum (8 mg/day OTC, 16 mg/day prescription), because the FDA warns that higher-than-recommended doses cause QT prolongation, torsades de pointes, and cardiac arrest; the TCA neuromodulator (e.g., amitriptyline, typically low-dose ~20 mg) is an off-label option reserved for loose-stool/idiopathic FI, and the AGS Beers Criteria recommend avoiding TCAs such as amitriptyline in older adults given their strong anticholinergic burden, sedation, orthostatic hypotension, and fall risk. Per the dedicated ASCRS 2023 fecal-incontinence guideline (updating ASCRS 2007, superseding reliance on ACG's broader 2021 anorectal-disorders guideline as the primary specialty source), sacral neuromodulation is a first-line surgical option for incontinent patients WITH OR WITHOUT a defined anal sphincter defect (conditional recommendation, low-quality evidence), it is not gated on documenting a sphincter defect. Sphincteroplasty remains appropriate for symptomatic patients with a defined external anal sphincter defect; repeat sphincteroplasty after a failed overlapping repair should generally be avoided in favor of other modalities. Antegrade continence enemas are an option before colostomy, which remains last resort.

In adults with chronic idiopathic constipation, the AGA-ACG panel makes 10 GRADE-based pharmacological recommendations, and the strength tier is part of the recommendation. Unqualified as to prior therapy: STRONG recommendation (moderate certainty) for polyethylene glycol; STRONG recommendation (moderate certainty) for bisacodyl or sodium picosulfate, but explicitly qualified as short-term or rescue therapy; CONDITIONAL suggestion for fiber supplementation (low certainty), magnesium oxide (very low certainty), and senna (low certainty). Reserved for patients who do not respond to, fail, or are intolerant of over-the-counter agents: STRONG recommendation (moderate certainty) for linaclotide, plecanatide, and prucalopride; CONDITIONAL suggestion for lubiprostone (low certainty) and lactulose (very low certainty). The guideline states no specific doses, no mandatory ordering algorithm, and no fixed trial duration; it notes only that nonpharmacological therapies 'often represent the initial steps in management' and directs clinicians to shared decision making incorporating patient preference, cost, and availability. The guideline explicitly does not cover anorectal evacuation disorders, referring those to the ACG 2021 benign anorectal guideline.