Gum chewing for bowel preparation

We read with great interest the article by Restellini et al. entitled: “Do adjuvants add to the efficacy and tolerance of bowel preparations? A meta-analysis of randomized trials” [1]. The authors should be commended for systematically assessing the role of most adjuvants in bowel preparation and providing appropriate recommendations for different clinical conditions where discrepancies exist between US and European guidelines. We agree with the authors that simethicone significantly improves bowel cleansing, which is also demonstrated by the findings of our recent multicenter randomized trial (P ˂ 0.001) [2]. In addition, our study also found that simethicone was associated with a higher adenoma detection rate and lower bloating rate (P ˂ 0.05), which resulted in a higher willingness to repeat colonoscopy in the future.

We wish to highlight however a potential adjuvant, gum chewing, that might have been excluded by the authors. Gum chewing, as a proxy for sham feeding, is a simple approach to increasing gut motility, and several trials have studied its effectiveness before colonoscopy as an adjuvant for bowel preparation. The first of these suggested gum chewing could improve bowel cleansing (P ˂ 0.001) and decease adverse events; however, the bowel cleansing agent used in this trial was high dose senna, which is rarely used in clinical practice because of possible adverse events [3]. The second trial investigated the effect of a combination of gum chewing and polyethylene glycol (4 L), and showed that gum chewing led to a remarkable reduction in abdominal discomfort (P = 0.015), and nausea and vomiting (P = 0.006) during bowel preparation [4]. Finally, our recent randomized trial further demonstrated that gum chewing could improve patients’ satisfaction with the process of bowel preparation and their willingness to repeat colonoscopy; in addition, it has no negative effects on cleanliness [5].

Overall, the findings of these trials consistently support improved tolerance of colonoscopy with gum chewing; however, none of them were included in the meta-analysis. Therefore, we just hope to remind the authors that gum chewing may be another choice of adjuvant for bowel preparation regimens.

^* Both authors contributed equally

• References

• 1 Restellini S, Kherad O, Menard C. et al. Do adjuvants add to the efficacy and tolerance of bowel preparations? A meta-analysis of randomized trials. Endoscopy DOI: 10.1055/s-0043-119638.
• 2 Bai Y, Fang J, Zhao SB. et al. Impact of preprocedure simethicone on adenoma detection rate during colonoscopy: a multicenter, endoscopist-blinded randomized controlled trial. Endoscopy DOI: 10.1055/s-0043-119213.
• 3 Ergul B, Filik L, Kocak E. et al. Efficacy and safety of gum chewing in adjunct to high-dose senna for bowel cleansing before colonoscopy: a single-blind randomized controlled trial. Saudi J Gastroenterol 2014; 20: 356-359
• 4 Lee J, Lee E, Kim Y. et al. Effects of gum chewing on abdominal discomfort, nausea, vomiting and intake adherence to polyethylene glycol solution of patients in colonoscopy preparation. J Clin Nurs 2016; 25: 518-525
• 5 Fang J, Wang SL, Fu HY. et al. Impact of gum chewing on the quality of bowel preparation for colonoscopy: an endoscopist-blinded, randomized controlled trial. Gastrointest Endosc 2017; 86: 187-191