Forty-four consecutive patients operated on with ileal J-pouchanal anastomosis (lPAA) and diverting ileostomy were examined with barium contrast medium of the pouch before closure of the ileostomy. CT was performed in 4 of the patients. The anatomy of the ileal reservoir as well as complications were assessed. As normal postoperative anatomy we found a "blind loop" at the upper part of the reservoir in 29 patients and a contrast lucency at the anastomosis between the anal channel and the pouch in 5 patients. Complications were revealed at barium contrast medium examinations in 13 patients, including stenoses at the anastomosis between the pouch and the anal channel in 8 patients and fistulas in 5 patients. CT was especially valuable in the exact diagnosis and location of a pelvic abscess in 3 patients, none of which was shown at pouchography.