A Patient Blinded, Randomized, Controlled Trial Comparing Right Colon Adenoma Detection Rate in Colonoscopy Using Right Colon Water Exchange and Traditional Air Insufflation

March 3, 2026 updated by: Dalin Tzu Chi General Hospital
Although colonoscopy is currently regarded as the gold standard to detect and prevent colorectal cancer (CRC) but post-colonoscopy CRCs (interval cancer, IC) still occur. Recent studies demonstrated that protection by colonoscopy against right-sided colon cancer was lower than that attained in the left colon. Adenoma detection rate (ADR) has been correlated with IC - each 1 % increase in ADR is associated with 3% decrease in the risk of ICs. Hopefully, innovations that improve right colon ADR would reduce the right colon IC. Insertion water exchange (WE), characterized by infusing water to guide the advance of the colonoscope in an airless lumen with its removal mainly during insertion. WE has been shown to improve the overall and right colon ADR compared to traditional air insufflation (Air). Several plausible causes have been proposed to explain the enhanced ADR by WE, including decreased multitasking related distraction, improved bowel cleanness, and flat polyps appearing less flatten and floating up in water Therefore, the adoption of WE in the right colon might be especially beneficial. In addition, WE has been criticized for prolonged insertion time, about 3-5 minutes longer than Air to reach the cecum and required a learning curve of about 50 to 100 cases.In this study, we devise a right colon WE method (RCWE), in which Air will be used to intubate to the hepatic flexure, followed by WE in the right colon. We test the hypothesis that RCWE would increase the right colon ADR without prolonging the insertion time. Consecutive patients undergoing screening, surveillance, or diagnostic examinations performed by participating endoscopists will be stratified for enrollment. Patients will be randomized in a 1:1 ratio (n=207 per group) to either the AI or RCWE group. Demographic data (age, gender, height, and weight), indications for colonoscopy, history of abdominal or pelvic surgery, constipation and chronic use of laxatives will be ascertained before colonoscopy. Quality of bowel preparation, cecal intubation time, withdrawal time, total procedure time, use of abdominal compression, need for change of position, presence and location of polyps and reasons for incomplete colonoscopy will be recorded. In addition, the right colon (from the hepatic flexure to cecum) insertion time and withdrawal time and infused and suction water amount will be recorded separately.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

414

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Taiwan
    • Chiayi
      • Chiayi City, Chiayi, Taiwan, 62247
        • Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Consecutive patients undergoing screening, surveillance, or diagnostic examinations performed by participating endoscopists will be stratified for enrollment.

Exclusion Criteria:

  • patient decline to give consent, age <40 years old, age >80 years old, previous partial colectomy, scheduled for polypectomy, not completely consumed bowel prep regimen, renal failure, massive ascites, and known colonic obstruction.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Right colon water exchange group
Air insufflation was used to advance the colonoscope to the hepatic flexure, where the insertion method was switched to water exchange (WE) to reach the cecum. This predefined transition was designed to specifically evaluate the effect of WE on right-sided colon adenoma detection.
Behavioral: Right colon water exchange
Air insufflation was used to advance the colonoscope to the hepatic flexure, where the insertion method was switched to water exchange (WE) to reach the cecum. This predefined transition was designed to specifically evaluate the effect of WE on right-sided colon adenoma detection.Air insufflation was applied during withdrawal in both groups.
Active Comparator: Air insufflation group
Cecal intubation was achieved using conventional air insufflation.
Behavioral: Air nsufflation
Behavioral: Air nsufflationAir was used to minimally distend the lumen during insertion. Water (30-50 mL aliquots) was delivered via syringe as needed to clear residual stool. Carbon dioxide was not used, as it is not standard practice for colonoscopy in Taiwan. Air insufflation was applied during withdrawal in both groups.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
adenoma detection rate in proximal colon
Time Frame: one week
The proportion of patients with the presence of adenoma in the proximal colon.
one week

Secondary Outcome Measures

Outcome Measure
Time Frame
adenoma detection rate
Time Frame: one week
one week

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Insertion time
Time Frame: 5 min
Right colon insertion time
5 min

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Dalin Tzu Chi General Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 9, 2020

Primary Completion (Actual)

December 31, 2025

Study Completion (Actual)

January 30, 2026

Study Registration Dates

First Submitted

March 3, 2026

First Submitted That Met QC Criteria

March 3, 2026

First Posted (Actual)

March 6, 2026

Study Record Updates

Last Update Posted (Actual)

March 6, 2026

Last Update Submitted That Met QC Criteria

March 3, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • A10802001-2

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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