The role of routine terminal ileal intubation (TII) in asymptomatic patients undergoing colonoscopy for colorectal cancer (CRC) screening or post-polypectomy surveillance is debated. While 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 post-polypectomy surveillance.

We conducted a systematic search of PubMed and Embase up to September 2025, according to PRISMA guidelines. We included studies reporting TII diagnostic yield in asymptomatic adults undergoing CRC screening or post-polypectomy 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, and the impact of TII on procedure duration.

Eleven studies involving 25659 patients, of whom 13672 underwent TII, were included. The pooled overall diagnostic yield for any ileal finding was 1.74% (95%CI 1.18%-2.57%), with most abnormalities being non-specific and not requiring clinical action. The diagnostic yield for clinically significant pathology was substantially lower at 0.28% (95%CI 0.07%-1.05%), while the yield for detecting Crohn’s disease was only 0.1% (95%CI 0.02%-0.44%), corresponding to one case per 1000 ileoscopies during colonoscopy for CRC screening.Across eight studies including 12,591 patients, ileal biopsies showed a very low diagnostic yield of 0.12%. Two studies found that terminal ileum intubation added about 56 seconds to procedure time, with no reported complications. Only two studies compared ileal findings across primary screening, FOBT-based screening, and post-polypectomy surveillance, preventing subgroup analysis. Limited data suggest similarly low diagnostic yields across groups: OR of 0.22 for primary screening and 0.1 for FOBT-positive patients, and overall yields of 1.9% (clinically significant 0.3%) for primary screening versus 4.0% (clinically significant 0.3%) for post-polypectomy surveillance. The studies showed variable methodological quality (NOS 4–8), mostly indicating moderate risk of bias. Sensitivity analyses showed no significant differences in diagnostic yield based on bias level or inclusion of non-TII patients, supporting the robustness of overall findings.

Routine TII in asymptomatic patients undergoing screening or surveillance colonoscopy provides a negligible diagnostic yield for clinically significant pathology, including Crohn's disease. Our findings do not support performing routine TII during colonoscopy in this patient population.