The authors studied the ileograms and computed tomographic (CT) examinations of 18 patients who had undergone surgical construction of an ileal J pouch and ileoanal anastomosis; 10 had developed postoperative infectious complications and eight had not. The initial ileograms obtained 4 weeks postoperatively proved to be unhelpful in predicting future infectious complications, showing abnormalities in only two of 10 patients. Ileography and CT performed at the time of the complications showed abnormalities in eight of nine and nine of 10 patients, respectively. Ileographic abnormalities in patients with abscesses included extravasation of contrast material, extraluminal gas collections, thickening of ileal pouch folds, and extrinsic mass effect on the pouch. CT findings included thickening of the pouch and/or rectal walls, streaky areas of soft-tissue attenuation within the ileal pouch mesentery and perirectal fat, and areas of soft-tissue attenuation or fluid attenuation in the peripouch region. CT was more valuable in depicting the site and extent of abscess formation before surgical or percutaneous drainage.