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

CT: computed tomography; CTE: computed tomography enterography; IBD: inflammatory bowel disease; MRE: magnetic resonance enterography; UGI/SBFT: upper gastrointestinal series with small bowel follow-through.

* Either MRE, CTE, or UGI/SBFT may provide evidence of small bowel disease, supporting the diagnosis of Crohn disease. MRE is favored to avoid radiation exposure. CT, with oral contrast (CTE) if possible, 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. UGI/SBFT can be used if MRE and CTE are not available.