The diagnosis of intra-abdominal abscesses in patients with severe Crohn's disease.

A series of 24 patients with severe relapses of Crohn's disease responding poorly to conventional treatment with corticosteroids was studied to determine the incidence of intra-abdominal abscesses and the best means to detect them. Ultrasound scans proved to be difficult to interpret and unreliable. Computed tomography demonstrated abnormal bowel thickening in most cases, and showed seven of the eight intraabdominal abscesses. 111In leucocyte scintigraphy always demonstrated inflamed areas of bowel, but underestimated the extent of disease in three patients and overestimated it in five. All eight abdominal abscesses were detected, and there were no false-positive results. It was always possible to distinguish the abscess from inflamed bowel wall. Intra-abdominal abscess is not uncommon in patients with severe relapses of Crohn's disease which are not responsive to corticosteroid therapy, being present in about one-third of patients. 111In leucocyte scintigraphy is a simple and helpful test for differentiating between active inflammatory bowel disease and complicating abscesses, contributing significantly to the management of patients with severe Crohn's disease.