Dynamic patient position changes during colonoscope withdrawal increase adenoma detection: a randomized, crossover trial

Gastrointest Endosc. 2011 Mar;73(3):456-63. doi: 10.1016/j.gie.2010.07.046. Epub 2010 Oct 15.


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).

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adenoma / diagnosis*
  • Adult
  • Aged
  • Aged, 80 and over
  • Cecum / pathology
  • Colon / pathology
  • Colonic Neoplasms / diagnosis*
  • Colonic Polyps / diagnosis*
  • Colonoscopy / methods*
  • Cross-Over Studies
  • Early Detection of Cancer / methods
  • Female
  • Humans
  • Male
  • Middle Aged
  • Patient Positioning*
  • Supine Position

Associated data

  • ClinicalTrials.gov/NCT00234650