Ileal Pouch-Anal Anastomosis: A Gastroenterology Perspective

Total proctocolectomy with an ileal pouch-anal anastomosis (IPAA) is the treatment of choice in medically refractory ulcerative colitis. Patients with an IPAA are at risk of developing pouch disorders, ranging from pouchitis, Crohn disease of the pouch, cuffitis, pouch neoplasia, and irritable pouch syndrome. Pouchitis is an aberrant mucosal immune response to altered luminal microflora and constitutes the leading cause of pouch dysfunction. A combination of clinical, serologic, and genetic factors may predict the likelihood of developing pouchitis. Endoscopy remains the gold standard in diagnosing pouch disorders. Inflammatory markers in blood as well as stool are useful in monitoring disease activity and can be followed for accurate prognostication. Most patients with pouchitis respond to a course of antibiotics; however, a few develop chronic relapsing pouchitis that may require long-term antibiotics or probiotics. All patients with chronic antibiotic refractory pouchitis should undergo evaluation for underlying enteric infections as well as Crohn disease. Treatment of Crohn disease of the pouch may require immunomodulators or biological agents. IPAA decreases but does not eliminate the risk of subsequent neoplasia in the residual rectal mucosa or the pouch itself. A systematic approach to diagnosing and classifying pouch disorders is imperative in managing patients' post-IPAA.