TOPLINE

Water exchange (WE) colonoscopy detected adenomas in 57.9% of colonoscopies compared to 44.0% with air insufflation—an absolute increase of 14 percentage points—with the greatest benefit in the right colon. It also improved bowel preparation quality, at the trade-off of a longer procedure.

METHODOLOGY

• A retrospective, propensity score–matched cohort study analyzed 4,322 outpatient colonoscopies (2,161 per group) performed at a high-volume center in Taiwan from January 2019 through October 2024.
• Three experienced endoscopists conducted all procedures, each with more than 15 years of experience and over 1,000 prior WE colonoscopies.
• The mean age was 59 years; 50% were men.
• WE used continuous water infusion with near-complete suction removal of luminal contents during insertion; the control group used conventional air insufflation.
• The primary outcome was adenoma detection rate (ADR). Other outcomes included segment-specific ADR, advanced adenoma detection, sessile serrated lesion (SSL) detection, bowel preparation quality assessed by the Boston Bowel Preparation Scale (BBPS), and procedure times.

TAKEAWAY

• WE increased overall ADR by 14 percentage points (57.9% vs 44.0%; P < .001), corresponding to a number needed to treat of 8. 
• Right-sided ADR increased by 13.8 percentage points with WE (31.8% vs 18.0%; P < .001), the largest gain among all colonic segments; WE improved detection of adenomas ≥10 mm (8.7% vs 6.7%; P =.014) and SSL (1.9% vs 1.0%; P =.011). 
• Mean total BBPS score was 1.1 points higher with WE (7.5 vs 6.4; P < .001), and adequate bowel preparation rate increased by 9 percentage points (97.4% vs 88.4%; P <.001). 
• Mean total procedure time was 7 minutes longer with WE (22.6 vs 15.6 minutes; P <.001), primarily due to longer cecal insertion time (11.0 vs 6.0 minutes; P <.001). 

IN PRACTICE

"An important finding of this study is that the magnitude of benefit (ADR +14.0%) persisted even against a high-performance baseline, where the air insufflation group’s ADR (44.0%) already substantially exceeded international benchmarks," the authors wrote.

SOURCE

The study was led by Ying-Ju Chao, Division of Gastroenterology, Department of Internal Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan. It was published online on July 27 in Therapeutic Advances in Gastroenterology.

LIMITATIONS

The retrospective single-center design with non-randomized group allocation based on patient preference and self-payment may have introduced unmeasured confounding. Endoscopists were not blinded to the insertion method. The inclusion of only 3 highly experienced endoscopists from a high-volume center limits generalizability to settings with varying operator expertise or lower procedural volumes. 

DISCLOSURES

The study was supported by a research grant from the Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.