Understanding Bowel Preparation Before Colonoscopy

It is extremely important that your colon be thoroughly cleaned before your colonoscopy. This will let the doctor see any abnormalities, such as colon polyps, during the procedure. Polyps are small growths in the colon that could later turn into cancer. Cleansing the colon before a colonoscopy is called bowel preparation, or prep. It involves taking medication that causes frequent, loose bowel movements to empty the colon. The medication is taken by mouth and typically comes in liquid form. You will also need to change what you eat during the day or two before the colonoscopy. Most bowel preparations involve drinking some prep liquid at two different times. The best way to cleanse the colon is with a “split-dose” bowel preparation. This involves drinking the first portion of the liquid preparation the evening prior to the colonoscopy, and then drinking the second part of the liquid preparation on the day of the colonoscopy. If your colonoscopy is scheduled to start in the morning, you must wake up early in the morning on the day of the colonoscopy to drink the second part of the prep. This can be an inconvenience for some people, but it gives your doctor the best chance of finding polyps or cancers in your colon. Taking both portions of the bowel preparation the evening prior to the colonoscopy, instead of taking the second portion of the prep on the morning of your colonoscopy, is an alternative option for cleansing the bowel. However, studies have shown that taking at least half of the prep solution on the same day as the colonoscopy provides the best bowel cleansing, which improves your doctor’s ability to find polyps and cancers in your colon. You should not drink any liquids (not even prep solution) within 2-3 hours of your colonoscopy. It is important that you understand the prep instructions given to you by your doctor, which will provide instructions on when you should drink your bowel prep.