Algorithm to guide the diagnosis of Crohn disease versus ulcerative colitis in children

IBD: inflammatory bowel disease; MRE: magnetic resonance enterography; CTE: computed tomography enterography; UGI/SBFT: upper gastrointestinal series with small bowel follow-through; CT: computed tomography.
* Either MRE, CTE, or UGI/SBFT may provide evidence of small bowel disease, supporting the diagnosis of Crohn disease. Where expertise in MRE is available, this technique is favored over CTE and UGI/SBFT to reduce radiation exposure. CT is an option used particularly in emergencies but generally is not recommended as first-line option for small bowel imaging, because of the radiation exposure.
¶ IBD-unclassified (IBD-U) was formerly termed "indeterminate colitis."