When surgery is necessary in patients with ulcerative colitis, total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the procedure of choice. Several inflammatory and noninflammatory complications can occur after IPAA. Pouchitis is the most common, occurring in approximately 50% of patients. Whereas "acute" pouchitis can be treated rapidly and successfully in the majority of patients, "refractory" and "chronic pouchitis" remain therapeutic challenges to patients and physicians. This article reviews the literature and offers consensus guidelines on issues related to the epidemiology, diagnosis, pathogenesis, risk factors, and treatment of pouchitis.