Position change during colonoscope withdrawal increases polyp and adenoma detection in the right but not in the left side of the colon: results of a randomized controlled trial

Background: It has been suggested that changing patient position during colonoscope withdrawal increases adenoma detection. The results of previous studies have been conflicting. Objective: To evaluate whether routine position change during colonoscope withdrawal improves polyp detection. Design: Randomized, 2-way, crossover study. Setting: Teaching hospital. Patients: A total of 130 patients attending for diagnostic colonoscopy. Interventions: Patients undergoing colonoscopy had each colon segment examined twice: the right side of the colon (cecum to hepatic flexure) in the supine and left lateral position and the left side of the colon (splenic flexure and descending colon) in the supine and right lateral position. The transverse colon was examined twice in the supine position. Main Outcome Measurements: The primary outcome measure was the polyp detection rate (>= 1 polyp) per colon segment. Secondary outcome measures included the number and proportion of patients with >= 1 adenoma in each segment and adequacy of luminal distension (1 = total collapse and 5 = no collapse). Results: Examination of the right side of the colon in the left lateral position significantly improved polyp detection (26.2% vs 17.7%; P = .01) and luminal distension (mean = 4.0 vs 3.5; P < .0001). Position change did not improve polyp detection in the left side of the colon (5.4% vs 4.6%; P = .99). There was no significant correlation between luminal distension and polyp detection in the right side of the colon (r = .03). Limitations: Single center and open study design. Conclusion: Examining the right side of the colon in the left lateral position increased polyp detection compared with examination in the supine position. Polyp detection in the left side of the colon was similar in the right lateral and supine positions.