Superiority of excellent over good bowel preparation for proximal serrated polyp detection in a fecal immunochemical test-based screening cohort

Background and aims: The proximal serrated polyp detection rate (PSDR) is an emerging quality indicator (QI) linked to postcolonoscopy colorectal cancer (CRC) risk, but the benefit of bowel cleanliness on its detection remains unclear. We evaluate the impact of excellent (Boston Bowel Preparation Scale [BBPS] 8-9) versus good (BBPS 6-7) preparation on serrated (PSDR and sessile serrated lesion [SSL] detection rate (SSLDR]) and adenoma-related (adenoma detection rate [ADR] and adenomas per colonoscopy [APC]) QIs in a fecal immunochemical test (FIT)-positive screening cohort. Methods: This retrospective single-center study of 1069 patients (aged 50-69 years) undergoing screening colonoscopy after a positive FIT compared PSDR, SSLDR, ADR, and APC between excellent and good preparation groups using univariate and multivariate regression analyses. Results: Excellent preparation showed a significantly greater PSDR (13.7% vs 7.9%; OR, 1.84; 95% CI, 1.22-2.80; P = .004) and SSLDR (7.6% vs 4.0%; OR, 2.00, 95% CI; 1.14-3.52; P = .016) than good cleansing. A linear relationship was observed, with BBPS 9 outperforming BBPS 8. No significant difference was found for ADR (50.4% vs 47.9%; OR, 1.10; 95% CI, 0.87-1.41; P = .424) and APC (mean difference = 0.103; 95% CI, -0.071 to 0.277; P = .247). Conclusions: Aiming for an excellent rather than a good bowel preparation is a critical strategy to maximize the detection rate of serrated pathway lesions and potentially reduce the incidence and mortality of interval CRC. This benefit does not extend to adenoma detection, underscoring the importance of PSDR and SSLDR as distinct and complementary QIs.