Cecal intubation time between the use of one‐channel and two‐channel water exchange colonoscopy: A randomized controlled trial

Background and Aim Water exchange (WE) colonoscopy is the least painful insertion technique with high adenoma detection rate but requires a longer intubation time. In the published literature, some investigators used the instrument channel for both infusing and suctioning of water (one channel), while others use colonoscopes with an integrated water‐jet channel specifically designed for infusing water (two channel). The aim of this study was to compare cecal intubation time between one‐channel and two‐channel WE. Methods A total 120 patients undergoing colonoscopy from May 2017 to April 2019 at a regional hospital in southern Taiwan were randomized to either a two‐channel group ( n  = 60) or a one‐channel group ( n  = 60). The primary outcome was cecal intubation time. Results The mean cecal intubation time was significantly shorter in the two‐channel group compared with the one‐channel group (14.0 ± 4.0 vs 17.4 ± 6.7 min, P  < 0.001). The two‐channel group required less water infused during insertion (564.8 ± 232.4 vs 1213.3 ± 467.5 mL, P  < 0.001) but achieved a significantly higher Boston Bowel Preparation Scale score (8.4 ± 0.8 vs 7.5 ± 1.1, P  < 0.001) than did the one‐channel group. The adenoma detection rate was comparable in the two groups (50.0% vs 48.3%, P  = 0.855). Conclusions In comparison with the one‐channel WE, two‐channel WE showed a shorter cecal intubation time, required less amount of water during insertion, and provided a better salvage cleansing effect. (NCT03279705)