Sporadic Adenoma Detection During Routine IBD Colonoscopies: A Secondary Analysis of Prospectively Collected Data

In colorectal cancer (CRC) screening, colonoscopy quality is assessed by sporadic adenoma detection and withdrawal time (WT). In inflammatory bowel disease (IBD), withdrawal is more complex due to IBD-specific tasks, such as targeted biopsies, dysplasia surveillance, and segmental inflammatory activity assessment. We hypothesized that in screening-age IBD patients in endoscopic remission, the yield of sporadic adenomas would be similar to that observed in non-IBD patients. We aimed to test this hypothesis recognizing that current quality benchmarks are extrapolated from non-IBD screening despite higher CRC risk in IBD.

We conducted a secondary analysis of prospectively collected colonoscopy data from a tertiary academic center. Our primary outcome was sporadic adenoma detection rate (ADR) in IBD, using non-IBD patients as a reference group. Secondary outcomes were mean WT, polyp detection rate, adenomas and polyps per colonoscopy, advanced adenoma detection rate, and sessile serrated lesion detection rate.

We analyzed 1366 colonoscopies (155 IBD;1211 non-IBD). When adjusting for WT and other potential confounders, ADR was significantly lower in IBD than in non-IBD (18.6% vs 43.0%). The increase in detection per additional WT minute was markedly attenuated in IBD: the odds of detecting an adenoma increased by 16.6% per additional minute in non-IBD versus 2.7% in IBD. Achieving a 26% ADR required an estimated WT of 6.8 min in non-IBD versus 28.2 min in IBD.

In a screening-age cohort without endoscopic IBD activity, our findings suggest that IBD-specific procedural demands limit effective inspection time, and other intrinsic characteristics of the surveillance context influence adenoma detection dynamics. Non-IBD quality thresholds may not be directly applicable to IBD, supporting the development of IBD-specific quality metrics.