Navigating Chronic Pouchitis: Pathogenesis, Diagnosis, and Management.

Chronic pouchitis affects 13% to 17% of patients with ileal pouch-anal anastomosis and ulcerative colitis, and 20% with a history of acute pouchitis. It is classified by antibiotic responsiveness into chronic antibiotic-dependent pouchitis and chronic antibioticrefractory pouchitis. Pathogenesis of chronic pouchitis can range from microbially mediated to more antibiotic-resistant and immune-mediated processes. A diagnostic index combining clinical, endoscopic, and histologic components is essential for clinical practice and research. In chronic antibiotic-dependent pouchitis, remission is managed with microbiota- or immune-targeted therapies. For chronic antibiotic-refractory pouchitis, immune-directed therapy is primary, with vedolizumab recommended for first-line treatment. Other advanced therapies rely on less definitive evidence, and efficacy may be reduced by precolectomy exposure. This article reviews the pathogenesis, diagnosis, and management of chronic pouchitis.