Impact of Intestinal Colonization with Clostridioides difficile on Clinical Outcomes in Alcohol-associated Hepatitis.

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.