Meta-analysis of randomized controlled trials challenging the usefulness of purgative preparation before small-bowel video capsule endoscopy

Abstract

Background: The usefulness of purgative preparation before small-bowel video capsule endoscopy is controversial. We aimed to examine the effect of purgative preparation on small-bowel video capsule endoscopy outcomes.

Methods: We performed literature searches in MEDLINE and the Cochrane library for randomized controlled trials evaluating the effect of purgative preparation (polyethylene glycol, sodium phosphate, others) vs. clear-liquid diet/fasting in patients undergoing small-bowel capsule endoscopy. Meta-analysis outcomes included the examination's diagnostic yield, small-bowel mucosal visualization quality, the examination's completion rate, and gastric and small-bowel transit times. The effect size on study outcomes was calculated using a fixed- or random-effect model, as appropriate, and is shown as the risk ratio (RR) with 95 % confidence interval (CI).

Results: We identified 12 eligible trials with 17 sets of data including 1221 subjects. Significant heterogeneity was detected with no evidence of publication bias. As compared with clear-liquid diet, purgative bowel preparation did not increase capsule endoscopy diagnostic yield (RR 1.17 [95 %CI 0.97 to 1.40]; P = 0.11). Neither the small-bowel mucosal visualization quality (RR 1.14 [95 %CI 0.96 to 1.35]; P = 0.15) nor completion rate for the examination (RR 0.99 [95 %CI 0.95 to 1.04]; P = 0.76) significantly improved after purgative preparation. Purgatives also had no effect on video capsule endoscopy gastric and small-bowel transit times.

Conclusions: Our analysis challenges the usefulness of purgative preparation for improving the diagnostic yield of small-bowel video capsule endoscopy and the quality of small-bowel mucosal visualization.