A Contrastive Study Of Water Exchange And Air Immersion Colonoscopy

Objective: Water exchange colonoscopy entailed complete exclusion of air insufflation. Removal of residual colonic air pockets and feces and suction of infused water occurred predominantly during insertion to minimize distention of the colonic lumen and abdominal pain. Some studies show that WEC can minimized the requirement for sedation, ease patients’ abdominal pain during colonoscopy, increase adenoma detection rate and cecal intubation rate. This study aims to access the impact of water exchange on abdominal pain and polyp detection rate, compared with air immersion.Methods: patients who underwent colonoscopy without sedation from June 2014 to December 2014 in endoscopy center 11 th floor were included in the study. According to inclusion and exclusion criteria, patients were randomly allocated into water exchange and air immersion. The main outcomes are maximum insertion pain score, polyp detection rate, cecal intubation time and cecal intubation rate.Result: 300 patients were randomly divided into 2 groups,150 in water exchange,150 in air immersion. There was significant difference between two groups about the maximum abdominal pain scores(mean±SD) during insertion(WEC 1.77±1.29 vs. AIC 2.84±1.55,P=0.000).The cecal intubation time was longer in WEC group(WEC 11.91±3.58 vs. AIC 8.03±3.19,P=0.000).Although polyp detection rate was higher in WEC group, there showed no significant difference between them(WEC vs. AIC,16.7% vs10.0%,P=0.089).The colonoscopic success rate between 2 groups was no significant difference(WEC vs. AIC,97.3% vs.94.0%,P=0.157).However, in the post abdominal and/or pelvic surgery subject of colonoscopy procedure, WEC group has higher success rate of intubation(WEC vs. AIC,100% vs75.9%,P=0.04)and lower maximum pain score(WEC vs. AIC, 2.25±1.63 vs3.48±1.45,P〈0.05).Conclusion: Water exchange colonoscopy can alleviate abdominal pain during colonoscopy, but a longer insertion time, without affect the polyp detection rate and cecal intubation rate. To the patient who had abdominal and/or pelvic surgery history, water exchange colonoscopy could enhance the colonoscopic success rate.