Inspection on instrument insertion during colonoscopy: a randomized controlled trial

Polyps seen and not removed during colonoscope insertion are sometimes unable to be found during withdrawal.

To investigate the impact of additional inspection during instrument insertion on adenoma detection in sedated patients undergoing routine screening or surveillance colonoscopy.

Randomized, controlled trial.

University hospital and associated ambulatory surgery center.

Patients undergoing elective screening or surveillance colonoscopy.

Patients were randomized to undergo colonoscopy with 3 minutes of dedicated inspection time during insertion plus 6 minutes during withdrawal versus 9 minutes of inspection on instrument withdrawal.

The primary outcome measure was the adenoma detection rate (proportion of patients with adenomas) between patients in whom inspection for adenomas was performed partly on instrument insertion compared with patients for whom inspection was performed entirely on withdrawal.

There was no difference in the proportion of patients with 1 or more adenomas between the inspection on insertion group (52%) and the inspection on withdrawal group (58%). There were no significant differences in total procedure time, time taken to remove polyps, sedation doses, or after-procedure pain between groups.

Single-center study with two endoscopists.

Inspection during colonoscope insertion offered no additional benefit compared with an equivalent period of inspection performed entirely during withdrawal. These results do not support an additional role for routine inspection during colonoscope insertion.