Dolichocolon (DC), an underrecognized anatomic variant characterized by colonic redundancy, is strongly linked to constipation. Its potential role in modifying inflammatory bowel disease phenotype has not been examined. We retrospectively evaluated pediatric patients with ulcerative colitis (UC) who underwent magnetic resonance enterography. DC was significantly more common in UC compared with Crohn disease and nonIBD controls, even in the absence of constipation. Subtype distribution differed by disease extent: Type 1 DC predominated in proctitis/left sided UC (E1/E2), whereas Type 2 DC was enriched in extensive/pancolitis (E3/E4). Complex DC (Types 1+2) was uniquely observed in UC. These findings suggest that DC may influence the anatomic localization and persistence of UC by altering colonic architecture, epithelial surface exposure, and host microbe interactions. DC may thus represent a congenital or developmental modifier of UC phenotype in children, warranting further investigation.

The authors have declared no competing interest.

No direct funding was received for this work

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