This report describes a 48-yr-old woman who had undergone proctocolectomy and ileostomy for ulcerative colitis. Subsequently, numerous episodes of bleeding via the ileostomy occurred during a 24-mo period. Despite numerous procedures, including upper gastrointestinal endoscopy, ileoscopy. celiac and superior mesenteric arteriography, and exploratory laparatomy, a bleeding site was not identified. However, a detailed arteriographic examination with special venous phase studies clearly demonstrated ileal varices. A mesocaval shunt resulted in a marked reduction in portal pressure, and the patient had experienced no recurrent bleeding over a 24-mo period. The importance of obtaining appropriate venous phase studies during arteriography is emphasized because it is critical in establishing the correct diagnosis.