Chewing gum for postoperative ileus after colorectal surgery: A systematic review of overlapping meta-analyses

Background Many meta-analyses investigating gum chewing for postoperative recovery after colorectal surgery have been published with inconsistent findings. Therefore, we performed this study to systematically review these overlapping meta-analyses and offer clinical recommendations based on the current best evidence for decision makers. Methods Multiple databases, including PubMed, EMBASE, Cochrane Library, Chinese BioMedical Literature on disc (CBMdisc), China National Knowledge Infrastructure (CNKI), Chinese Wanfang and Chinese VIP, were searched through October 2016. We included meta-analyses investigating the effectiveness of chewing gum for postoperative ileus after colorectal resection. Two investigators independently scanned and evaluated eligible meta-analyses, extracted essential information, assessed the methodological quality with the Assessment of Multiple Systematic Reviews (AMSTAR) tool and Oxford Levels of Evidence, and used the Jadad decision algorithm at each step for all procedures. Heterogeneity ≤50% was accepted. Results Ten meta-analyses were included in our study. The AMSTAR scores varied from 5 to 9, with a median of 7.7. Most heterogeneity fell into the acceptable range. After implementing the Jadad decision algorithm, two meta-analyses of RCTs were selected based on search strategies and the implications of selection. The available best evidence indicated that gum chewing significantly reduced time to first flatus, time to first bowel movement, time to first bowel sounds and length of hospital stay. However, these two meta-analyses reached inconsistent conclusions as to the complications and economic benefits. Conclusions With the current best available evidence, we suggest gum chewing is beneficial for gastrointestinal function and reducing postoperative ileus.