A 56-year-old, male patient presented with abdominal pain and watery diarrhea. Computed tomography demonstrated thickening of the terminal ileal wall. A colonoscopy was attempted but the terminal ileum was too narrow to admit colonoscope. So, a sliding tube of small bowel balloon endoscopy was placed for nasal endoscope insertion. The nasal endoscope was passed through the stenotic area, where multiple ulcers were observed. The biopsy found no malignancy. Based on these findings, Crohn's disease was suspected, and treatment with mesalamine and prednisone was begun. In this case, the ulcers ware monitored for relapses during treatment by using nasal endoscope. This method is safe and useful for evaluating stenotic areas that are difficult to pass through with a colonoscope.
