Your healthcare team will give you plenty of time to prepare. You will get instructions at least two weeks before the procedure. It is important to read and follow all of the instructions given to you. If your bowel is not empty, your colonoscopy will not be successful and may have to be repeated. The cleaner your colon, the better chance your provider will have at finding all of your polyps and cancer, which sometimes can be small or hidden. The time of day or night that you will have to start drinking the solution will depend on when your procedure is scheduled. You will be asked to consume the entire amount of liquid within a specific time period. There is also something called “split-dosing.” In split dosing, you will be asked to drink half of the bowel preparation the night before and then stop. You will get up in the morning and do the other half of the dose in the morning, finishing up at least four hours before the procedure itself. In general, split dosing results in cleaner bowel preparations. If you are having a colonoscopy with conscious sedation or twilight, and you have not been given split dosing instructions, ask your provider if you can do the split dosing.