How you prepare

By Mayo Clinic Staff

Before a virtual colonoscopy, you'll need to empty your colon. Any residue in your colon may obscure the images taken during the exam.

To empty your colon, follow your doctor's instructions carefully. You may be asked to:

  • Follow a special diet the day before the exam. Typically, you won't be able to eat that day. Drinks may be limited to clear liquids. You may not be able to eat or drink anything after midnight the night before the exam.
  • Take a laxative the night before the exam. You may also need to use a suppository to clear any remaining residue in your colon.
  • Take medication to identify stool in your colon. The medication will help the doctor differentiate between colon abnormalities and stool residue.
  • Adjust your usual medications. Remind your doctor of your medications at least a week before the exam. You may need to temporarily stop taking certain medications days or hours before the exam.
Jun. 09, 2014