Gastroenterology Services

Preparing for your colonoscopy (English)
Preparing for your colonoscopy (Spanish)



A colonoscopy is a visual exam of the inner lining of the large intestine (colon) to check for growths, colorectal polyps and other abnormalities. Your doctor may perform a colonoscopy to screen for colon cancer or evaluate other experienced problems, including blood loss, abdominal or rectal pain, changes in bowel habits or persistent bleeding.

Preparing for the procedure

Your colon must be empty prior to the procedure. There are different ways empty your colon in order to prepare for a colonoscopy. Your doctor will advise the best preparation method for you as well as specific drinking and eating instructions. It is important to make sure you get additional instructions from your doctor prior to the procedure if you are:

  • Diabetic
  • Taking a blood thinner
  • Have experienced a heart attack or stroke in the past six months
  • Have an artificial heart valve or heart defibrillator
  • If you may be pregnant

Your doctor may give you a prescription laxative tablet or drink solution the evening before your scheduled exam. Nausea is a common side effect of the laxative due to the bitter taste. Ask your doctor if it's ok for you to drink clear liquids or lemon juice to neutralize the taste of the laxative. Do not eat any solid foods after taking the laxative. It is important to follow the instructions provided by your physician's office.

During the procedure

While lying on your left side with your knees pulled inward, a flexible tube (a colonoscope) with a camera at the end is inserted into the rectum to view your colon. Polyps or growths found during the procedure are typically removed and sent to the lab for further testing. It is normal to feel cramping or the need to have a bowl movement during the procedure. The test usually takes 20-30 minutes, depending on what your doctor finds during the exam. You will need to arrange for transportation home from the hospital since a sedative and intravenous pain medication is administered before the procedure.