Diagnosis and differential diagnosis of Crohn's disease of the ileal pouch.

Approximately 20%-30% of patients with ulcerative colitis will eventually require colectomy despite recent advances in medical therapy. Ileal pouch-anal anastomosis has become the surgical treatment of choice. A subset of patients with ileal pouches can develop Crohn's disease or a Crohn's-disease-like condition of the ileal pouch after surgery. Diagnosis, differential diagnosis, and management of Crohn's disease of the ileal pouch have been challenging. A combined assessment of clinical history, endoscopy, histology, abdominal/pelvic imaging, and examination under anesthesia is often necessary for accurate diagnosis, disease classification, management, and prognosis. A multidisciplinary approach with gastroenterologists, colorectal surgeons, gastrointestinal pathologists, and radiologists is advocated.