Routine terminal ileum intubation and biopsy: A standard practice for colonoscopy completion

Background and objectives

Terminal ileum intubation is considered the completion step of colonoscopy and is usually performed to assess the ileum. The histological examination of the ileal mucosa, which is acquired during terminal ileum intubation, may allow an accurate diagnosis. However, there is no absolute consensus on when ileoscopy and biopsy should be attempted. As a result, we aimed to evaluate whether terminal ileum intubation and biopsy should be performed routinely.

Methods

Systematic searches were performed in the PubMed, EMBASE, and Cochrane Library databases, as well as the Science Citation Index via the Web of Science platform. Reference lists from the identified papers were manually searched. Systematic searches were performed from January 1, 1971, to October 1, 2025. Studies reporting on terminal ileum intubation and biopsy during colonoscopy were included. Case reports, letters, reviews, and animal studies were excluded. The primary outcomes were the diagnostic yield of terminal ileum intubation and the rate of necessitating a change in management. Data were extracted independently by three reviewers.

Results

Thirty-six studies were included. The subtotal diagnostic yield and the rate of necessary change among the selected patients were much greater than those among the unselected patients (5.1% versus 2.5% and 1.5% versus 0.4%, respectively). In addition, the diagnostic yield was found more frequently for inflammatory bowel disease, anemia, abdominal pain, and chronic diarrhea than for the other indications (26.7%, 16.1%, 14.9%, 12.4%, and 3.2%, respectively). The yield of ileal histopathology with a normal endoscopic appearance was low in both unselected and selected patients (3.5% and 2.4%, respectively).

Conclusions

Terminal ileal intubation is the gold standard for completing colonoscopy. It has a vital role in the diagnostic process. We recommend that TI intubation be adopted as standard practice and attempted in all patients with photo documentation. In cases with abnormal mucosal findings or red-flag symptoms-particularly diarrhea, suspected IBD, abdominal pain, or anemia-biopsy should be obtained.