Abstract:Objective To explore the safety and effectiveness of painless colonoscopy within 2 hours after bowel preparation.Methods 120 volunteers were randomly divided into observation group and control group. The observation group received rapid bowel preparation and the control group received conventional bowel preparation. The incidence of nausea and vomiting, the completion rate of the examination, the time-consuming of the examination, the incidence of aspiration during the examination, polyp detection rate and the Boston Bowel Preparation Scale (BBPS) scores were compared between the two groups during the bowel preparation process.Results The two groups of volunteers all completed the examination. During the examination, there were no adverse events such as vomiting or aspiration. The average examination time of the observation group and the control group were (15.50 ± 4.41) and (17.07 ± 4.43) min, the polyp detection rate was 28.3% (17/60) and 31.7% (19/60) respectively, there was no statistically significant difference between the two groups (P > 0.05). The incidences of nausea and vomiting during bowel preparation in the two groups were 36.7% (22/60) and 63.3% (38/60) respectively, and the BBPS scores were (8.88 ± 0.32) and (8.63 ± 0.55), respectively, there were statistically significant difference between the two groups (P < 0.05).Conclusion For healthy people who have no symptoms of digestive tract, in the case of rapid bowel preparation, a painless colonoscopy can be performed 2 hours after bowel preparation, which does not increase the chance of aspiration, does not affect the quality of bowel preparation, and can significantly reduce the nausea and vomiting during bowel preparation.