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How I Teach My Trainees “Water Navigation Colonoscopy”


Colonoscopy is a difficult examination for inexperienced examiners, often due to over-insufflation of air, causing elongation of the colon and patient pain. Sedation medications relieve pain, which is a warning sign of perforation. We describe the water navigation method. With the patients in the left lateral position, air removal from recto-sigmoid allows the injected water to flow into the descending colon through the ‘collapsed’ lumen, improving the view. The “cork-screw twist” maneuver facilitates the passage of the colonoscope through the “straightened” sigmoid colon without pain. Under supervision by the author, six novices were allowed to insert the colonoscope within ten minutes by this method in one patient per week, as long as the patients did not complain of pain. The average number of attempts for the first cecal intubation within ten minutes was 3.3, and the average success rate during the first three months was 58.6%.