Defying Occam’s Razor: Colonic Luminal Endometriosis in an Adolescent With Crohn's Disease

Abstract Abdominal pain is a common symptom in Crohn's disease, presumably associated with mucosal inflammation and/or luminal stenosis. However, pain is not specific to Crohn's disease, and other etiologies should be considered, particularly gynecologic pathology in an adolescent female. We present an unusual case of endometrial tissue found in the colonic polyp of an adolescent with known Crohn's disease and abdominal pain. Histologic analysis differentiated endometriosis from active inflammation secondary to Crohn's disease. Endometriosis and Crohn's disease are both classified as chronic inflammatory disorders. It remains unclear whether overlapping etiological factors exist for the two disorders. There is a paucity of data on comanagement of endometriosis and inflammatory bowel disease, especially in adolescents. Given the finding of endometriosis in the colonic polyp was unanticipated, this case also reinforces the merits of endoscopic staging of disease whenever significant changes in therapy are considered.