Ultrasound examinations were performed in 36 patients with Crohn's disease, 28 with ulcerative colitis, and 50 with no bowel disease. The pathological findings were classified into three types and compared with the radiographic and/or colonoscopic findings. Crohn's disease and ulcerative colitis could be detected by ultrasonography with a sensitivity of 86% and 89%, respectively. The ultrasonographic features correlated with the radiographic/colonoscopic findings and with disease activity, but did not help much in making a differential diagnosis, although the location of the pathologic changes was helpful to some extent. In conclusion, ultrasonography can serve as a useful alternative diagnostic procedure that permits us to obtain information about transmural changes in inflammatory bowel disease.