To observe the effect of compound polyethylene glycol electrolyte powder (PEGP) combined with paraffin oil in bowel preparation in constipation patients.?Methods?120 constipation patients who were going to undergo colonoscopy were randomly divided into group A and B. Group A took oral PEGP 278.24 g 6h before colonoscopy, and group B took oral PEGP 139.12 g, and oral paraffin oil 50 ml for 1 day before colonoscopy. Both groups were fed a diet of less dregs 1 d before the examination, and fasting on the day of the examination was completed. The endoscopic physician recorded the patient’s tolerance, adverse reactions, colonoscopy time, and conducted the Boston intestinal preparation scale (BBPS) and the intestinal bubble score.?Results?Effectiveness for intestinal preparation, group B colonoscopy examination time was (7.25?±?0.60) min, less than group A (10.50?±?0.55)?min (P?