Radiographic imaging studies have an important role in the workup of patients with suspected IBD and in the differentiation of ulcerative colitis and Crohn's disease. Because of its ability to depict fine mucosal detail, the double-contrast barium study is a valuable technique for diagnosing ulcerative colitis and Crohn's disease even in patients with early disease. In contrast, cross-sectional imaging studies such as CT, MR, and ultrasound are useful for showing the effects of these conditions on the wall of the bowel and also for demonstrating intra-abdominal abscesses and other extraluminal findings in patients with more advanced disease. Thus, barium studies and cross-sectional imaging studies have complementary roles in the evaluation of these patients.