Related Experiment Video
Updated: Jun 8, 2026

Structured Approach to Colonoscopy Technique Optimization: A Single-Center Experience with Novice Endoscopists
Published on: July 11, 2025
Dynamic patient position changes during colonoscope withdrawal increase adenoma detection: a randomized, crossover
James E East1, Paul Bassett, Naila Arebi
1Wolfson Unit for Endoscopy, St. Mark’s Hospital, Imperial College London, London. jameseast6@yahoo.com
Background:
Colonoscopy has a miss rate for adenomas that may partly relate to poor visualization of the colonic surface. Dynamic position changes during colonoscope withdrawal can improve luminal distension.
Objective:
To assess whether position changes also improve adenoma and polyp detection.
Design:
Randomized crossover clinical trial.
Setting:
Academic endoscopy unit.
Patients:
This study involved 130 patients who presented for routine colonoscopy.
Intervention:
Examination either entirely in the left lateral position followed by position changes (cecum to hepatic flexure, left lateral; transverse colon, supine; splenic flexure and descending colon, right lateral) or vice versa. After both examinations, polyps were removed for histopathology.
Main Outcome Measurements:
Proportion of patients with ≥1 polyp or adenoma detected between the hepatic flexure and the sigmoid-descending colon junction. Luminal distension was measured on a scale of 1 to 5: 1, total collapse; 5, fully distended.
Results:
At least 1 adenoma was detected in 34% of patients in colon areas in which the patient position differed from left lateral (transverse colon, splenic flexure, descending colon) compared with 23% examined with the patient in the left lateral position alone (P = .01). At least 1 polyp was detected in 52% of patients with position changes versus 34% of patients examined in the left lateral position alone (P < .001). Adenoma and polyp detection were positively correlated with an improved distension score (correlation coefficient, 0.12; P < .001). Adenomas were detected in 16% of colon areas with adequate distension scores (4 and 5) compared with 7% of those with borderline or nondiagnostic scores (1-3; P < .001).
Limitations:
Single-operator study.
Conclusion:
Dynamic position changes during colonoscope withdrawal significantly improved polyp and adenoma detection. (
Clinical Trial Registration Number:
NCT00234650).
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...
Assessment of the Rectum and Anus
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
Endoscopic Procedures III: Video Capsule Endoscopy
Lower GI Series: Barium Enema
Procedure Details
The examination begins by inserting a lubricated rectal tube into the patient's rectum to administer a radiopaque barium solution. The barium flow is carefully...
