Water Exchange vs. CO₂ Insufflation During Colonoscopy

CO₂ insufflation reduces postprocedural discomfort in sedated patients and may reduce intraprocedural discomfort more than air insufflation in unsedated or lightly sedated patients.

To determine whether water exchange during colonoscope insertion controls discomfort more effectively than CO₂ insufflation, investigators conducted a prospective, multicenter, randomized study of 473 patients at three endoscopy centers in Norway and Poland. All patients were unsedated, and only about 5% of all approached patients declined participation, as the study was performed in Northern European centers where unsedated colonoscopy is routine. Patients were randomized to water exchange during insertion versus CO₂ insufflation.

Fewer patients experienced moder…