Water as contrast medium for computed tomography study of colonic wall lesions.

A tap water enema combined with intravenous iodine contrast medium was used for computed tomographic (CT) study of the entire clean colon in 35 patients. Thirty of them showed a high suspicion of rectal, colon, or cecal pathology at either clinical examination, barium enema study, or endoscopy. The remaining five patients were examined for suspected local recurrence of carcinoma. This CT technique detected the wall abnormality in all but one case with two small adenomatous polyps. This procedure, which is simple, inexpensive, and has a good acceptance and tolerance, can accurately detect mural wall abnormalities.