Improving the view during flexible sigmoidoscopy: a systematic review of published randomized, controlled trials comparing the use of oral bowel preparation versus enema bowel preparation.

To systematically analyse the published randomized, controlled trials (RCTs) comparing the use of oral bowel preparation (OBP) versus enema bowel preparation (EBP) for diagnostic or screening flexible sigmoidoscopy. Published RCTs, comparing the use of OBP versus EBP, were analysed using RevMan(®), and the combined outcomes were expressed as odds ratios (OR). Eight RCTs evaluating 2457 patients were retrieved from the standard electronic databases.