Colonoscopies are vital for detecting and how long does a colonoscopy take, but many wonder about the duration of the procedure. The Procedure: A colonoscopy typically takes about 30 minutes to an hour. This includes the time for preparation, sedation, the examination itself, and recovery. Preparation: Before the procedure, patients must undergo bowel preparation, which involves fasting and taking a laxative solution to clear the colon. This preparation usually takes several hours.