Abstract: Objective?To explore the effect of chewing gum on bowel preparation before colonoscopy in patients with constipation.?Methods?68 patients with constipation underwent colonoscopy from November 2017 to December 2018 were divided into control group and observation group according to the random number table method, 34 cases in each group. The control group used conventional bowel preparation. On the basis of the control group, the patients in the observation group were chewed with sugar-free chewing gum, and the intestinal cleanliness, polyp detection rate and adverse reaction occurred between the two groups were compared and analyzed.?Results?In the observation group, the score of the right colon cleansing effect was significantly higher than that of the control group. The other colon cleansing scores and total scores were higher than the control group, but the difference was not obvious. The observation group detected 7 small polyps, the detection rate was 20.6%, 6 patients with small polyps were detected in the control group, the detection rate was 17.6%, the difference was not statistically significant (P > 0.05); 16 patients with small polyps were detected in the observation group, and 10 small polyps were detected in the control group. The number of small polyps detected in the observation group was significantly higher than that in the control group (P < 0.05). The incidence of nausea, vomiting, poor sleep, abdominal pain and abdominal distension in the observation group were significantly lower than those in the control group. Academic significance (P < 0.05).?Conclusion?In patients with constipation, colonoscopy is performed by conventional SF-PEG combined with chewing gum. It can effectively improve the intestinal cleansing effect, complete intestinal preparation, reduce the residual of the lesion, and reduce the occurrence of adverse reactions, recommended clinical promotion.