Effect of Bowel Preparation to Colonoscopy Interval on Preparation Quality and Colonoscopy Outcomes: A Meta-Analysis

This study evaluates the effect of bowel preparation to colonoscopy time interval on quality of bowel preparation and outcomes of colonoscopy.

Studies were identified after a literature search in electronic databases and were selected for inclusion based on precise eligibility criteria. Meta-analyses of proportions were performed to achieve overall bowel preparation adequacy and adenoma/polyp detection rates. Odds ratios depicting associations between bowel preparation quality and bowel preparation to colonoscopy time were pooled to achieve an overall estimate.

Twenty studies (10 341 individuals subjected to colonoscopy) were included. Bowel preparation adequacy rate was higher with shorter (94% [95% CI: 91, 97]) than with longer (84% [95% CI: 79, 89]) interval between bowel preparation and colonoscopy. In a subgroup analysis, <5, 6-10, 11-20, and >20 hours intervals were associated with 94% [95% CI: 92, 97], 92% [95% CI: 86, 96], 85% [95% CI: 77, 91], and 85% [95% CI: 75, 92] adequacy rates, respectively. A pooled analysis of odds ratios also showed that bowel preparations adequacy was significantly better with shorter bowel preparation to colonoscopy time (odds ratio 1.69 [95% CI: 1.23, 2.15]). There was no significant difference in adenoma detection rate between shorter (18% [95% CI: 9, 29]) and longer (19% [95% CI: 15, 22]) bowel preparation to colonoscopy intervals. Polyp detection rate was higher with shorter (47% [95% CI: 27, 68]) than with longer (30% [95% CI: 24, 38]) bowel preparation to colonoscopy interval.

A shorter interval between bowel preparation and colonoscopy led to a higher bowel preparation adequacy rate which was also associated with a higher polyp detection rate.