Impact of seasonal variation in bowel preparation quality on colonoscopy outcomes: a prospective observational study

INTRODUCTION: Bowel preparation quality is a key determinant of colonoscopy performance and lesion detection. However, the impact of seasonal variation on bowel preparation remains insufficiently understood. This study aimed to evaluate the effect of bowel preparation quality on colonoscopy outcomes and investigate the roles of seasonal variation and fluid intake.
METHODS: In this prospective observational study, 1,110 patients undergoing elective colonoscopy were included. Bowel preparation quality was assessed using the Boston Bowel Preparation Scale (BBPS). The cecal intubation rate, withdrawal time, polyp detection rate (PDR), and adenoma detection rate (ADR) were analyzed. The effects of seasonal variation and fluid intake were also evaluated.
RESULTS: Adequate bowel preparation was achieved in 90.5% of patients. Inadequate preparation was associated with lower cecal intubation rates, shorter withdrawal times, and reduced lesion detection (PDR: 21.0% vs. 34.7%, p=0.006; ADR: 16.2% vs. 26.9%, p=0.023). Adequate fluid intake significantly improved BBPS scores (p=0.001). Seasonal analysis demonstrated significantly poorer bowel preparation quality during winter (p<0.001).
DISCUSSION AND CONCLUSION: Bowel preparation quality significantly influences colonoscopy performance and lesion detection. The poorer preparation quality observed during winter suggests that seasonal factors should be considered. Optimizing hydration and accounting for environmental factors may improve colonoscopy quality.

Keywords: Adenoma detection rate, bowel preparation, colonoscopy, hydration, polyp detection rate, seasonal variation