Meta-analysis of randomized controlled trials challenging the usefulness of purgative preparation before small-bowel...

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.

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).

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.

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.