A randomized controlled trial assessing the effect of prescribed patient position changes during colonoscope withdrawal on adenoma detection

Background: High-quality colonoscope withdrawal technique is associated with a higher adenoma detection rate. Position change is routinely used in barium enema and CT colonography to facilitate adequate distension of the colon and promote movement of fluid from the segment of the colon being assessed.

Objective: To determine whether prescribed position changes during colonoscope withdrawal affect the adenoma detection rate compared with the usual care per endoscopist.

Design: Prospective, randomized, controlled trial.

Setting: Tertiary-care, university-affiliated hospital.

Patients: Patients referred for outpatient colonoscopy between July 2011 and July 2012 were evaluated for eligibility. Inclusion criteria were outpatient status and age ≥40 years. Exclusion criteria were (1) complete colonoscopy within 1 year before the procedure, (2) inability to provide informed consent, (3) incomplete colonoscopy to the cecum, (4) previous bowel resection, (5) inflammatory bowel disease, (6) colonic polyposis syndrome, (7) inadequate bowel preparation, and (8) musculoskeletal disorder or other mobility issues limiting effective patient position changes during colonoscopy.

Interventions: Prescribed position changes during colonoscope withdrawal.

Main outcome measurements: Polyp detection rate (PDR) and adenoma detection rate (ADR).

Results: A total of 776 patients were enrolled, with 388 in the dynamic group. There was no difference in PDR (odds ratio [OR] 0.99; P = .93) or ADR (OR 1.17; P = .28). Colonoscope withdrawal time was longer in the dynamic group (median time 466.5 vs 422.5 seconds; P < .0001).

Limitations: Single-center study. Indication for procedure not controlled. Lack of standardized bowel preparation and blinding.

Conclusion: Prescribed position changes during colonoscope withdrawal do not affect polyp/adenoma detection compared with the usual practice when the baseline ADR is above the recommended standard. (

Clinical trial registration number: NCT01395173.).