What to Expect on the Day of a Colonoscopy

A colonoscopy is an imaging procedure that examines your colon’s lining. A doctor recommends a colonoscopy to screen for cancer and other gut-related disorders. A colonoscopy is an important screening test because it allows doctors to identify precancerous polyps and remove them before they turn into cancer.

According to the U.S. Preventative Task Force, regular screening is recommended every 10 years for all adults age 50 to 75 or sooner if you have inflammatory bowel disease such as Crohn’s or ulcerative colitis, a family history of colorectal polyps or colorectal cancer, or a genetic syndrome like Lynch disease that increases your risk of colon cancer.

Woman in colonoscopy procedure room with medical staff
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Before the Procedure

Your colon has to be completely empty to not only allow the scope to pass through the colon but to also allow your doctor the greatest visibility during the procedure. Proper preparation is important to ensure that your doctor can detect any potential abnormalities inside the colon.

Arrange for someone to help you home once the procedure is complete as the medications administered during the procedure can cloud your judgment and affect your reflexes.

Bowel Prep

Before the procedure your doctor will prescribe a colonoscopy preparation aimed at emptying the colon of fecal matter. Be sure to clear your schedule after noon of the day before the procedure and be close to a restroom during this time.

These instructions may include:

  • Avoid high-fiber foods, including seeds and nuts, for up to a week prior to your colonoscopy.
  • Avoid solid food for one day prior to the procedure (including absolutely nothing two hours before the procedure).
  • Drink plenty of clear fluids the day before the test. Clear liquids include water, clear broth, coffee and tea (without milk), ice, or gelatin.
  • Avoid red and purple liquids, which can be mistaken for blood in the colon during the procedure.
  • Drink a strong laxative solution to empty your bowels the afternoon or evening prior to the procedure to clean your colon sufficiently for the procedure.

Sometimes drinking the laxative solution is more unpleasant than the actual colonoscopy procedure. Some people find it easier to drink by refrigerating the solution and drinking it through a straw.

It is important to follow these instructions completely to ensure that the procedure goes as smoothly as possible. Throughout the entire prep period it’s important to drink lots of fluids because keeping hydrated not only clears your colon but also maintains your electrolyte balance.

During the Procedure

A colonoscopy may be performed at an outpatient center, clinic, or hospital. You will check in and change into a hospital gown.

An anesthesiologist or nurse anesthetist will give you a medication that makes you feel groggy. Your vitals, including your blood pressure, heart rate, pulse oximetry, and temperature will be monitored throughout the procedure.

The procedure is performed while laying on your side. A gastroenterologist uses a scope called a colonoscope to identify areas of bleeding or abnormal growth.

The colonoscopy procedure involves inserting a thin scope with a light on the end into the rectum. A small, non-painful burst of air is blown through the colon to widen the area. The gastroenterologist advances the scope through the colon to examine it.

They may remove samples of tissue for biopsy or remove an outgrowth of tissue known as a polyp. The entire procedure takes between 30 and 60 minutes. Rarely do people report feeling pain during a colonoscopy.

After the Procedure

You may feel groggy after the procedure due to the anesthetic that you're given just prior to your colonoscopy. For this reason, healthcare professionals recommend that you have a family member or friend pick you up after your procedure.

If the procedure is completed without complications you should go home the same day. It's common to feel quite hungry after the procedure so you will be transitioned to solid foods soon after the procedure is complete.

While it’s normal to have some blood in your stool after the procedure, call a healthcare professional if you are concerned about blood in your stool or experience severe abdominal pain as this may be indicative of a perforated colon, a rare complication of the colonoscopy procedure.

If you experience unexplained weight loss, fever, chills, or anxiety as you wait for your results do not hesitate to contact your gastroenterologist or a healthcare provider.

Your doctor will usually give you a preliminary result of your colonoscopy soon after the procedure. Your results can include:

If your results are normal, you will not have to do the procedure for 10 years unless otherwise indicated. If a polyp is discovered, a biopsy is taken. It can take up to two weeks to receive your results. Normally, your doctor calls you to communicate the results of your colonoscopy.

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  1. U.S. Preventive Service Task Force. Colorectal cancer screening: Final recommendation statement. June 15, 2016.