Related Experiment Video
Updated: Jun 25, 2026

Structured Approach to Colonoscopy Technique Optimization: A Single-Center Experience with Novice Endoscopists
Published on: July 11, 2025
Impact of a novel water method on scheduled unsedated colonoscopy in U.S. veterans
Felix W Leung1, H Steven Aharonian, Joseph W Leung
1Department of Medicine, Division of Gastroenterology, Research and Medical Services, Sepulveda Ambulatory Care Center, VAGLAHS, North Hills, California, USA. felix.leung@med.va.gov
Background:
Intermittent warm-water infusion in lieu of air insufflation permitted 52% of patients who accepted sedation on demand to complete colonoscopy without sedation.
Objective:
To test the hypothesis that the water method enhances cecal intubation and increases the proportion of patients who report willingness to repeat a scheduled unsedated colonoscopy.
Design:
Observational study.
Patients:
Two consecutive groups of veterans.
Interventions:
From June 2005 to May 2006, the usual air insufflation method was used to aid colonoscope insertion. From June 2006 to October 2007, the water method was used.
Main Outcome Measurements:
Cecal intubation; report of willingness to repeat unsedated colonoscopy.
Results:
Sixty-two and 63 veterans were examined by the air method and the water method, respectively. Intention-to-treat analysis revealed that the cecal intubation rate with the water method (97% [61/63]) was significantly higher than that with the air method (76% [47/62]). The proportion of patients who reported willingness to repeat unsedated colonoscopy was significantly higher with the water method (90% [57/63]) compared with the air method (69% [43/62]).
Limitations:
Single site, nonrandomized, unblinded, small number of elderly male veterans.
Conclusion:
The effects of the water method in the group for scheduled unsedated colonoscopy were sufficiently provocative to warrant calling for their confirmation by a randomized controlled trial.
Related Concept Videos
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and solid...
Endoscopic Procedures II: Colonoscopy
Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...
Endoscopic Procedures III: Video Capsule Endoscopy
