A 40-year-old woman was admitted to our emergency department with chief complaints of lower abdominal pain and frequent diarrhea. Abdominal computed tomography (CT) showed edematous thickening of the entire small intestine, and lower gastrointestinal endoscopy showed irregular and map-like ulcers in the ileum. Biopsy showed inflammatory changes, with no findings of collagen bands, vasculitis, or amyloidosis. However, her symptoms did not improve, and abdominal contrast-enhanced CT showed exacerbation of the edematous changes. We suspected familial Mediterranean fever because blood tests revealed elevated serum amyloid S levels. We administered colchicine was administered as diagnostic treatment, but symptoms did not improve. Given the edematous changes in the small intestine seen on abdominal contrast-enhanced CT, we suspected drug-induced enteritis. Once vonoprazan was discontinued, her symptoms gradually improved and she was discharged without recurrence of abdominal symptoms. Subsequent outpatient abdominal CT showed improvement of the edematous changes in the small intestine.
