CT adds valuable information in the assessment of inflammatory bowel diseases in children. Although early mucosal changes are best shown by barium studies, extramucosal and extraintestinal abnormalities are best visualized with CT. CT can be used to differentiate the various extramucosal abnormalities that may have similar appearances on barium studies, including bowel wall thickening, abscess, phlegmon, or adenopathy. Although many inflammatory conditions of bowel may have similar appearances on CT scans, a careful analysis of the appearance of the bowel wall and the associated extraintestinal abnormalities, combined with a review of the clinical and laboratory data, enables a specific diagnosis to be made in many cases.