The Effect Of Dimethicone Powder Taken At Different Time On Colon Visualization During Colonoscopy

Objective:Dimethicone powder is a defoaming agent commonly used in colonoscopy.It is used in combination with laxatives to eliminate bubbles in the bowel preparation and improve the visibility of bowel mucous during colonoscopy.However,the best time to taking dimethicone powder has not been determined in the guideline for bowel preparation of China.The purpose of this study was to explore the effects of adding dimethicone powder in PEG-ELS at different times on bowel visualization,and to find the best time for taking dimethicone powder.Methods:A prospective,randomized,controlled study was conducted on360 patients who underwent colonoscopy in the First Affiliated Hospital of Guangxi Medical University from October 2019 to September 2020.The patients were divided into group A,B,C and D with 90 cases in each group by random number table method.18 patients were withdrawn from this study due to treatment of distal colonic polyps,discovery of colorectal masses or bowel stenosis that could not complete the whole colonoscopy.So 342 patients were finally included in this study.Group A,Group B and Group C were taken 2.5grams of dimethicone powder 6 hours,4 hours and 2 hours before colonoscopy,respectively.Group D did not take dimethicone powder.The bowel cleaning quality,bowel bubbles,examination duration,polyp detection rate and adenoma detection rate of the four groups were compared.Result:There was statistically significant difference in the amount of bowel bubbles among the 4 groups(P<0.05).The total bowel bubble scores of the experimental group(groups A,B and C)were lower than that of the group D.while the score of total bowel bubble in group A was the lowest,and there were significant differences between groups A and B,A and C,B and D,C and D(P<0.05).The overall difference in polyp detection rate and adenoma detection rate was statistically significant(P<0.05),while the polyp detection rate and adenoma detection rate of the control group in Group D were the lowest,and there were statistically significant differences between groups B and C,groups C and D(P<0.05).In terms of bowel cleaning quality and examination duration,there were no statistical significance among the 4 groups(P>0.05).Conclusion:In bowel preparation before colonoscopy,adding dimethicone powder into polyethylene glycol solution can effectively reduce the amount of bowel bubbles,achieve the effect of eliminating bubbles,and improve the visibility of bowel mucosa,and increase the detection rate of polyps or adenomas.However,when dimethicone powder was taken 6 hours before the colonoscopy,the amount of bowel bubbles was lower and the effect of eliminating bubbles was better.