Abstract：Objective： To explore the efficacy of calcium polycarbophil combined with polyethylene glycol electrolyte powder (PEG) in bowel preparation before colonoscopy. Methods： A total of 225 patients receiving colonoscopy at the Digestive Endoscopy Center of Shanghai Eighth People′s Hospital, from November 2021 to October 2022 were enrolled in the study. The patients were randomly divided into three groups: 4 L-PEG group, 2 L-PEG+calcium polycarbophil group and 4 L-PEG+calcium polycarbophil group, 75 cases in each group. Aronchick score, Boston bowel preparation scale (BBPS) score, detection rate of polyps, adenomas and other lesions, antifoam effect score, patient tolerance rate, willingness to re-accept, and adverse reaction events were recorded and analysed. Results： Compared with 2 L-PEG+calcium polycarbophil group and 4 L-PEG group, Aroncheck score in 4 L-PEG+calcium polycarbophil group was significantly decreased (P<0.05), and total BBPS score, left half, middle and right half colon scores were significantly increased (all P<0.05). There was no difference in the detection rates of adenoma and polyp among the three groups (all P>0.05). The antifoam effect score of 4 L-PEG + calcium polycarbophil group was better than that of 2 L-PEG+calcium polycarbophil group and 4 L-PEG group (P<0.05). The tolerance rate of 2 L-PEG+calcium polycarbophil group was significantly higher than that of 4 L-PEG group (P=0.001). The proportion of reacceptance willingness of 2 L-PEG+calcium polycarbophil group was higher than that of the other two groups (both P<0.012 5). The proportion of abdominal distension in 2 L-PEG+calcium polycarbophil group was greatly lower than that in the other two groups (P<0.01). There were no significant differences in the comparison of nausea, vomiting, abdominal pain, dizziness and headache among 3 groups (P>0.05). Conclusion： The intestinal cleansing effect of calcium polycarbophil combined with PEG was more effective than that of PEG alone, the combination of 2 L-PEG and calcium polycarbophil had the similar intestinal cleansing effect as that of 4 L-PEG, and had better tolerance, higher willingness to reacceptance, less adverse events. ［Key words］colonoscopy; intestinal preparation; compound polyethylene glycol electrolyte powder; calcium polycarbophil
