Efficacy of Gum Chewing on Bowel Movement After Open Colectomy for Left-Sided Colorectal Cancer: A Randomized Clinical Trial.

Background: Prolonged intestinal paralysis can be a problem after gastrointestinal surgery. Several systematic reviews and meta-analyses have suggested the efficacy of gum chewing for the prevention of postoperative ileus.

Objective: The purpose of this study was to examine the efficacy of gum chewing for the recovery of bowel function after surgery for left-sided colorectal cancer and to determine the physiological mechanism underlying the effect of gum chewing on bowel function.

Design: This was a single-center, placebo-controlled, parallel-group, prospective randomized trial.

Settings: The study was conducted at a general hospital in Japan.

Patients: Forty-eight patients with left-sided colorectal cancer were included.

Interventions: The patients were randomly assigned to a gum group (N = 25) and a control group (N = 23). Four patients in the gum group and 1 in the control group were subsequently excluded because of difficulties in continuing the trial, resulting in the analysis of 21 and 22 patients in the respective groups. Patients in the gum group chewed commercial gum 3 times a day for ≥5 minutes each time from postoperative day 1 to the first day of food intake.

Main Outcome Measures: The time to first flatus and first bowel movement after the operation were recorded, and the colonic transit time was measured. Gut hormones (gastrin, des-acyl ghrelin, motilin, and serotonin) were measured preoperatively, perioperatively, and on postoperative days 1, 3, 5, 7, and 10.

Results: Gum chewing did not significantly shorten the time to the first flatus (53 ± 2 vs. 49 ± 26 hours; p = 0.481; gum vs. control group), time to first bowel movement (94 ± 44 vs. 109 ± 34 hours; p = 0.234), or the colonic transit time (88 ± 28 vs. 88 ± 21 hours; p = 0.968). However, gum chewing significantly increased the serum levels of des-acyl ghrelin and gastrin.

Limitations: The main limitation was a greater rate of complications than anticipated, which limited the significance of the findings.

Conclusions: Gum chewing changed the serum levels of des-acyl ghrelin and gastrin, but we were unable to demonstrate an effect on the recovery of bowel function.