Abstract It is uncertain whether terminal ileum intubation should be performed routinely during colonoscopy, as there is uncertainty regarding its diagnostic value. The aim of the present study is to assess the diagnostic yield of terminal ileum intubation during colonoscopy according to indications for colonoscopy. This is a cross-sectional study in which the results of 294 total colonoscopy procedures were reviewed; ileal intubation was performed in 269 (91.49%) patients. The indications for colonoscopy, the results of ileoscopy, and the histopathological results of ileal biopsies were evaluated. A total of 54 (20%) out of 269 patients who had successful intubation into the terminal ileumshowed macroscopic abnormalities on the terminal ileum. Biopsies were positive in 4 out of 54 (7.4%); all were of Crohn disease. Two were erosions (9.5%.) and 2 were ulcers (18.8%). The two erosions were presented as abdominal pain, abdominal pain and alternating bowel motion. Those with ulcers were presented with diarrhea and perianal disease. Conclusions Considering the low diagnostic yield of ileal intubation during colonoscopy, the decision to performileoscopy or not during colonoscopy needs to bemade on a case-by-case basis. However, routine ileal intubation, brief attempts should be considered despite low diagnostic yield. (AU)