A meta-analysis on timing of bowel preparation in colonoscopy: Same-day versus evening before

Abstract

Significance:
Bowel preparation is fundamental to achieving good quality colonoscopy. However, technological advances and improvement in endoscopy skill are not accompanied by improvement in patient compliance to bowel preparation. To date, there are no guidelines regarding timing of bowel preparation for afternoon colonoscopy. The aim of this study is to compare and clarify issues regarding quality of bowel preparation (primary endpoint), and patient satisfaction and cecal intubation rate (secondary outcomes).

Methodology:
Systematic search was done using PubMed, Cochrane, clinicaltrials.gov and Google Scholar. Randomized clinical trials comparing effects of same-day bowel preparation to evening before in patients undergoing colonoscopy were included. Abstracts were reviewed independently by the authors and study eligibility determined by consensus. Combined data were analyzed using RevMan 5.3 software.

Results:
Six articles were identified from literature search, but two were excluded. Primary outcome shows no significant difference among pooled studies, RR 1.05 (95%, CI 0.96–1.15), with significant heterogeneity. Cecal intubation has RR of 0.99 (95%, CI0.97-1.01) without statistical significance. Patient satisfaction has RR 0.39 (95% CI 0.29-0.54), favoring same-day preparation without statistically significant heterogeneity.

Conclusion:
Benefit of same-day compared with evening-before bowel preparation is suggested but not firmly established based on currently available evidence. Further studies are needed. Overall patient satisfaction and willingness to repeat bowel preparation are factors to be considered for bowel preparation compliance in order to achieve successful colonoscopy.