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Gastrointest Endosc. 2017 Jun;85(6):1273-1280. doi: 10.1016/j.gie.2016.11.030. Epub 2016 Dec 6.

Adenoma miss rates associated with a 3-minute versus 6-minute colonoscopy withdrawal time: a prospective, randomized trial.

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Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.



The 6-minute withdrawal time for colonoscopy, widely considered the standard of care, is controversial. The skill and technique of endoscopists may be as important as, or more important than, withdrawal time for adenoma detection. It is unclear whether a shorter withdrawal time with good technique yields an acceptable lesion detection rate. Our objective was to evaluate a 3-minute versus a 6-minute withdrawal time by using segmental tandem colonoscopy.


We performed a prospective, randomized trial by using 4 expert endoscopists. Patients were randomized to a 3-minute or a 6-minute initial withdrawal, each followed by a tandem second 6-minute withdrawal. All polyps were removed. The primary outcomes were adenoma miss rates (AMRs), adenomas per colonoscopy (APC) rates, and adenoma detection rates (ADRs).


A total of 99 and 101 patients were enrolled in the 3-minute and 6-minute withdrawal groups, respectively. The AMR was significantly higher in the 3-minute withdrawal group (48.0% vs 22.9%; P = .0001). After controlling for endoscopist, patient age and/or sex, Boston Bowel Preparation Scale score, and size and/or location and/or morphology of adenoma, the AMR remained significantly higher in the 3-minute withdrawal group (odds ratio, 2.78; 95% confidence interval, 1.35-5.15; P = .0001). The ADR was similar between both groups (39.2% vs 40.6%; P = .84). However, the mean APC rate was significantly lower in the 3-minute withdrawal group (0.55 vs 0.80; P = .0001).


The AMR was significantly higher, and the APC rate was significantly lower in the 3-minute withdrawal group versus the 6-minute withdrawal group. Despite expert technique, a shorter withdrawal time is associated with an unacceptably high AMR and low APC rate. (Clinical trial registration number: NCT01802008.).

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