Sham feed or sham? A meta-analysis of randomized clinical trials assessing the effect of gum chewing on gut function after elective colorectal surgery.

Purpose: Enhanced recovery programs aim to expedite gut function after elective colorectal surgery. Early oral feeding simulates gut function but is not always feasible. Gum chewing, a form of sham feed, is an alternative. We assessed current evidence for gum chewing and gut function.

Study Design: All randomized controlled trials (RCTs) between 1990 and 2008 comparing gum chewing with controls/placebo were analyzed irrespective of language, blinding, or publication bias. The Jadad scale was used to assess study quality. Endpoints were time to flatus/feces, postoperative complications, and hospital stay. Random and fixed models were employed to aggregate study endpoints and assess heterogeneity.

Results: Six RCTs containing 256 patients were included. Significant heterogeneity was identified and random effects model was employed. Heterogeneity may be explained through variations in delivery of surgical care. Significant reductions in the time to flatus and time to feces were identified but no significant difference in hospital or in-hospital postoperative complications were found.

Conclusions: Gum chewing significantly reduced time to flatus and feces; however, hospital stay and postoperative complications were not reduced. Significant study heterogeneity means that these results should be interpreted with caution.