BACKGROUND: Inflammatory bowel disease (IBD) is well recognized in developed countries and is generally among the differential diagnoses of young patients presenting with refractory diarrhea once other more common etiologies have been excluded. Pinworm infections, on the other hand, are not as common among adults in the United States.

CASE REPORT: Based on computed tomography features, a 24-year-old female patient with a history of multiple autoimmune disorders presented with abdominal pain and was diagnosed recently with Crohn’s disease. Colonoscopy was significant for pinworms seen throughout the colon. Colonic biopsy was negative for inflammatory bowel disease (IBD)-related changes.

CONCLUSIONS: The diagnosis of IBD is a serious label that requires biopsy confirmation before committing to possibly life-long treatment and possible adverse effects. Even in the most typical patient and when the presentation and imaging are classical, uncommon conditions (like Enterobius infection in this case) may preclude appropriate diagnosis and management.

Keywords: Biopsy, Colonoscopy, Crohn Disease - diagnosis, Diagnosis, Differential, Enterobiasis - parasitology, Enterobius - isolation & purification, Tomography, X-Ray Computed