Positive Cologuard Test Makes for Longer Colonoscopy Time

Previous studies show that performing colonoscopy for a positive imaging test (computed tomographic colonography or double contrast barium enema) leads to a considerably longer colonoscopy procedure time, perhaps specifically because of difficulty or inability to find a false positive lesion.

In the current single-center study, U.S. investigators examined whether the indication of a positive multi-target stool DNA test (Cologuard) affected colonoscopy results and performance. They evaluated colonoscopies performed on 172 patients with known positive Cologuard test and 72 control patients with positive Cologuard test who underwent blinded colonoscopies (i.e., the endoscopist was unaware whether the test was positive or negative) as part of an earlier clinical trial.

In the unblinded colonoscopy group, detection of any polyp was 78% versus 60% in the blinded colonoscopy group (P<0.01), and the percentage of patients with any sessile serrated polyp or conventional adenoma was 70% versus 53%, respectively (P=0.01). Findings of slightly raised lesions in the right colon were more frequent in the unblinded versus the blinded group (40% vs. 9%; P<0.01). Medium withdrawal time was longer in the unblinded group (19 vs. 13 minutes; P=0.0001).