Colonic transformation of ileal pouch-anal anastomosis and of the distal ileum: MRI findings.

Colonic metaplasia of the ileal reservoir in patients after ileal pouch-anal anastomosis (IPAA) is described in pathological and histochemical studies. So far, there are no reports on the imaging presentation of colonic transformation. We describe the distinctive post-operative MRI features found in a 28-year-old patient with IPAA after failed conservative treatment of chronic ulcerative colitis. These distinct MRI features of colonic transformation of ileum mimicking normal colon are important to know for radiologists reading MR examinations of patients with IPAA.