During the past decade, the medical and surgical treatment of ulcerative colitis has undergone dramatic advances, including the widespread use of immunomodulators, biological drugs, and restorative proctocolectomy. In order to correctly balance the risks and benefits of medical therapies and surgical procedures, there is a need for improved diagnosis of colonic disease, acute complications, extraintestinal manifestations, and early and delayed postoperative complications. Cross-sectional imaging techniques are therefore playing an increasing role in the assessment of ulcerative colitis and...