Pen Foreign Body Ingestion Mimicking Crohn's Disease in a Pediatric Patient.

Foreign body ingestion is common in pediatrics, particularly in children with psychiatric illness. Foreign bodies present for extended periods of time can trigger a local inflammatory reaction causing weight loss, abdominal pain, and elevated inflammatory markers, mimicking inflammatory bowel disease (IBD). We report a case of intentional pen ingestion in a 13-year-old, whose clinical presentation with elevated inflammatory markers and terminal ileitis suggested on imaging was initially suspicious for Crohn's disease but was found on colonoscopy to be due to foreign body reaction from ingestion of a pen.