Ileal Pouch Physiology: Clinical Implications

Abstract Patients with severe ulcerative colitis and familial adenomatous polyposis often need proctocolectomy. Usually, they are offered gastrointestinal reconstruction with an ileal pouch-anal anastomosis, where a reservoir or pouch is created out of the terminal ileum and anastomosed to the anus. This allows per anal defecation with continence and avoids the need for a permanent ileostomy. The downside of the ileal pouch-anal anastomosis is its physiology, which relies on gravity for evacuation and offers inadequate protection for the ileal mucosa against bacterial invasion. As a result, patients with an ileal pouch-anal anastomosis are prone to inefficient defecation, leading to straining, nighttime stooling, increased frequency of stooling, fecal stasis, bacterial overgrowth, and incontinence. Management of these symptoms involves investigation to diagnose correctable conditions, strategic changes in lifestyle and diet, judicious surgery where necessary, and medications aimed at improving evacuation and treating fecal stasis. Patients need to understand the physiology of their pouch and that they are subject to a new way of defecation.