Grocery Coupons

Grocery Coupons

Members can print free savings coupons

Brain Health Center

Brain Health Center

Learn how to live smart and stay sharp

Amazon Kindle

Amazon Kindle

Members save on e-
readers and tablets

Caring for loved ones?

Caring for loved ones?

Find the resources you need


Diseases & Conditions A - Z
powered by healthline


What Is a Colonoscopy?

Colonoscopy is a procedure that uses a thin, flexible camera to check for abnormalities or disease in your lower intestine or colon.

The colon is the lowest portion of the gastrointestinal tract—the series of organs that takes in food, absorbs nutrients, and disposes of waste. The colon is attached to the anus, the opening in your body where feces are expelled.

During a colonoscopy, your doctor may also take tissue samples for biopsy. He or she may also remove abnormal tissue such as polyps.

Why a Colonoscopy Is Performed

A colonoscopy can be done as a pre-emptive screening for colon cancer and other problems. The screening can help doctors:

  • look for signs of cancers and other problems
  • explore the cause of unexplained changes in bowel habits
  • evaluate symptoms of pain or bleeding located in the abdominal area
  • find a reason for weight loss, chronic constipation, or diarrhea

The U.S. Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer. Fecal occult blood testing, sigmoidoscopy, or colonoscopy is used to test adults from ages 50 to 75. According to the American College of Surgeons, everyone over the age of 50 who is at average risk of colon cancer should get a colonoscopy once every 10 years. If your risk is higher, you may need more frequent procedures. Between 76 and 90 percent of colon cancer can be prevented through colonoscopies (American College of Surgeons).

The Risks of a Colonoscopy

Since a colonoscopy is a routine procedure, there are typically few lasting effects from this test. The benefits of detecting problems and beginning treatment far outweigh the risks of complications from a colonoscopy.

However, some rare complications include:

  • bleeding from a biopsy site, if a biopsy is done
  • reaction to the sedative
  • tear in the rectal wall or colon

How to Prepare for a Colonoscopy

Your doctor will give you complete instructions for your “bowel prep,” which sounds much more traumatic than it actually is. Basically, it means you must have a clear liquid diet for 24 to 72 hours prior to your procedure. The typical bowel prep diet includes:

  • bouillon or broth
  • gelatin
  • plain coffee or tea
  • pulp-free juice
  • sports drinks, such as Gatorade

Make sure not to drink any liquids containing red or purple dye, as they may discolor your colon. That means if you’re drinking sports drinks, the red and purple flavors are off-limits.

Inform your doctor of any medications—including over-the-counter drugs or supplements—you are taking. Some may affect your colonoscopy, and if so, your doctor may tell you to stop taking them. These might include blood thinners, vitamins that contain iron, and certain diabetes medications.

Your doctor will give you a laxative to take the night before your appointment. He or she may also advise you to use an enema at the same time, or the day of the procedure.

You may want to arrange for a ride home after your appointment. You’ll want the sedative to fully wear off before getting behind the wheel.

How a Colonoscopy Is Performed

Just before your colonoscopy, you’ll change into a hospital gown. Most people receive some type of sedative, usually in pill form.

During the procedure, you’ll lie on your side on a padded examination table. Your doctor may position you with your knees close to your chest to get a better angle to your colon.

While you’re on your side and sedated, your doctor will guide a flexible, lighted tube called a colonoscope into your anus. Slowly and gently, he or she will guide it up through the rectum and into the colon. A camera on the end of the colonoscope transmits images to a monitor that your doctor will be watching.

Once the scope is positioned, your doctor will inflate your colon using carbon dioxide gas. This gives him or her a better view.

Depending on what your doctor finds—or what he or she suspects prior to the test— your doctor may remove polyps or a tissue sample for biopsy during this procedure. You’ll be awake during your colonoscopy, so your doctor will be able to tell you what is happening.

The entire procedure takes about 30 minutes to an hour.

After a Colonoscopy

After the procedure is done, you’ll wait for about an hour to allow the sedative wear off. You’ll be advised not to drive for the next 24 hours, until its full effects fade.

In addition, you’ll also typically experience some gas and bloating from the gas your doctor blew into your colon. Give this time to get out of your system. If it continues for days after, it could be signaling a problem and you should contact your doctor.

Also, a little bit of blood in your stool after the procedure is normal. However, if you continue to pass blood or blood clots, experience abdominal pain, or have a fever over 100°F, call your doctor.

If your doctor removed tissue or a polyp during a biopsy, it will be sent to a laboratory for testing. Your doctor will inform you of the results when they are ready, normally within a few days.

Content licensed from:

Written by: Brian Krans
Medically reviewed : George Krucik, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.
Symptom Search
Enter your symptoms in our Symptom Checker to find out possible causes of your symptoms. Go.
Drug Interaction Checker
Enter any list of prescription drugs and see how they interact with each other and with other substances. Go.
Pill Identifier
Enter its color and shape information, and this tool helps you identify it. Go.
Drugs A-Z
Find information on drug interactions, side effects, and more. Go.
AARP Driver Safety


Discounts & Benefits


tax form

AARP Foundation Tax-Aide

Find a free Tax-Aide location
near you.

AARP In Your Corner

Visit Black Community, Español  and Asian Community pages.

AARP Drivers Safety logo

Driver Safety Program

Register at a location near you to keep your driving skills sharp. 

Create The Good 

Find opportunities to volunteer in your neighborhood. 

AARP Drive to End Hunger logo

Drive to End Hunger

NASCAR champ Jeff Gordon teams up with AARP's Foundation. 


Green Dot Prepaid Card

Prepaid MasterCard

AARP Foundation Prepaid MasterCard brought to you by Green Dot.

Most Popular


Nothing has been viewed