Diagnostic yield and usefulness of terminal ileal intubation in asymptomatic patients undergoing colonoscopy for colorectal cancer screening or postpolypectomy surveillance: a systematic review and meta-analysis

BACKGROUND AND AIMS: The role of routine terminal ileal intubation (TII) in asymptomatic patients undergoing colonoscopy for colorectal cancer (CRC) screening or postpolypectomy surveillance is debated. Although considered a quality indicator in some settings, its clinical utility in this population remains unclear. This systematic review and meta-analysis aimed to evaluate the diagnostic yield, clinical utility, and procedural impact of routine TII in patients undergoing CRC screening or postpolypectomy surveillance. METHODS: We conducted a systematic search of PubMed and Embase up to September 2025, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included studies reporting TII diagnostic yield in asymptomatic adults undergoing CRC screening or postpolypectomy surveillance colonoscopy. Data were synthesized using random-effects models. The primary outcome was the overall diagnostic yield of TII. Secondary outcomes included the diagnostic yield for clinically significant findings, Crohn's disease (CD), and the impact of TII on procedure duration. RESULTS: Eleven studies involving 25,659 patients were included, of whom 13,672 underwent TII. The pooled overall diagnostic yield for any ileal finding was 1.74% (95% CI, 1.18-2.57), with most abnormalities being nonspecific and not requiring clinical action. The diagnostic yield for clinically significant pathology was substantially lower at 0.28% (95% CI, 0.07-1.05), whereas the yield for detecting CD was only 0.1% (95% CI, 0.02-0.44), corresponding to 1 case per 1000 ileoscopies during colonoscopy for CRC screening. CONCLUSIONS: Routine TII in asymptomatic patients undergoing screening or surveillance colonoscopy provides a negligible diagnostic yield for clinically significant pathology, including CD. Our findings do not support performing routine TII during colonoscopy in this patient population.