Abstract:ObjectiveTo observe the effect and the patient acceptance of oral lactulose in bowel preparation before colonoscopy diagnosis and treatment. MethodsA total of 560 patients, who were scheduled to undergo colonoscopy for diagnosis and treatment in Anorectal Center of Nanjing Hospital of TCM from May 2021 to May 2022 were selected as research subjects and were randomly divided into observation group(n=289) and control group(n=271). Lactulose plus drinking water （1 500mL） and compound polyethylene glycol electrolyte plus drinking water （4000mL） were taken orally, respectively in observation group and control group. The basic information, intestinal cleanliness, acceptance of medication, foam formation, pathological changes and adverse reactions were observed and compared between two groups. ResultsThere were no significant differences in Boston score, bubble size and detection rate of colorectal polyps between two groups （P＞0.05）. In observation group, the patient acceptance for preparation medication doses was higher than that in control group(P＜0.05), the incidence of nausea and vomiting was significantly lower than that in control group(P＜0.05), and the incidence of dry mouth and fatigue was higher than that in control group （28.37%vs3.69%, χ2=7.862, P＜0.05； 10.73%vs3.32%, χ2=3.275, P＜0.05）. There was no significant differences in terms of abdominal distension, abdominal pain, dizziness and headache between two groups （P＞0.05）. ConclusionLactulose oral solution is safe, reliable and effective, with few adverse reactions and good patient acceptance in intestinal preparation before colonoscopy diagnosis and treatment.