Striving for Perfection in Bowel Cleansing: Impact of Good vs. Excellent Preparation on Colorectal Lesion Detection

Aims Bowel preparation is a critical factor for high-quality colonoscopy. Adequate preparation, defined as a Boston Bowel Preparation Scale (BBPS) score>5, is associated with a higher adenoma detection rate (ADR), a key quality indicator of screening colonoscopy. However, the impact of excellent preparation (BBPS 8-9) compared to good preparation (BBPS 6-7) on ADR remains controversial.

Methods This study is a post-hoc analysis of data from two prospective comparative trials conducted within a population-based screening program. We analyzed polyp and adenoma detection rates according to histology and location based on BBPS classification.

Results Among 4011 colonoscopies, 1032 had good preparation (BBPS 6-7) and 2730 had excellent preparation (BBPS 8-9). Colonoscopies with good preparation detected a significantly higher number of polyps (2.384±2.847 vs. 2.030±2.634, p=0.0003) and adenomas (1.496±2.106 vs. 1.281±1.934, p=0.0031) compared to those with excellent preparation. Similarly, good preparation was associated with increased detection of advanced polyps (0.444±0.870 vs. 0.351±0.738, p=0.0011), proximal polyps (0.689±1.345 vs. 0.552±1.202, p=0.0026), advanced adenomas (0.384±0.785 vs. 0.288±0.623, p=0.0001), and proximal adenomas (0.512±1.098 vs. 0.385±0.922, p=0.0004). Detection rates of flat adenomas, serrated lesions, and sessile serrated lesions (SSL) were comparable between groups (p>0.05). Notably, advanced proximal adenomas were more frequently detected in the good preparation group (0.103±0.395 vs. 0.056±0.278, p<0.0001).

Conclusions Excellent bowel preparation does not confer a detection advantage over good preparation. Paradoxically, good preparation is associated with a higher detection rate of advanced and proximal lesions. This could be attributed to the need for additional mucosal cleaning, leading to a more meticulous inspection and enhanced identification of subtle lesions. These findings suggest that while striving for excellent bowel cleansing is logical, a good level of preparation may provide unexpected benefits in colorectal cancer screening programs.

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Artikel online veröffentlicht:
27. März 2025