Clinical and radiographic findings were reviewed for four patients in whom colonic diverticulitis was suspected clinically but in whom small intestine ischemia was proved surgically. In each patient the initial diagnostic studies--plain abdominal radiography and barium enema examination--revealed generalized small intestine distention and non-specific colonic abnormalities, respectively. The latter findings consisted of an extrinsic impression on the superior or inferior aspect of the sigmoid colon with associated thumbprinting or spiculation. In each patient serosal inflammation of the sigmoid colon produced by an adherent segment of the ischemic small intestine was confirmed at laparotomy. In two patients, delay in surgical intervention resulted in small intestine necrosis. In a patient who has clinical signs and symptoms of colonic ischemia, diverticulitis, or small intestine obstruction but nonspecific findings on barium studies, the diagnosis of small intestine ischemia should be considered and further diagnostic imaging, such as angiography or small intestine follow-through examination, should be performed.