Colonoscopy is a procedure used to see inside the colon and rectum. Colonoscopy can detect inflamed tissue, ulcers, and abnormal growths. The procedure is used to look for early signs of colorectal cancer and can help doctors diagnose unexplained changes in bowel habits, abdominal pain, bleeding from the anus, and weight loss.

Video: What to Expect During a Colonoscopy

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

How to Prepare for Colonoscopy

The doctor usually provides a prescription and written instructions about how to prepare for colonoscopy. This process is called a bowel prep. Generally, all solids must be emptied from the gastrointestinal tract by following a clear liquid diet for 1 to 3 days before the procedure.

Patients should not drink beverages containing red, blue, or purple dye. Some acceptable liquids include:

  • bouillon or broth (chicken or wonton)
  • fruit juice - apple or white grape/cranberry juices
  • water - fitness waters are fine also
  • plain coffee or plain tea - in moderation
  • ice pops - no sherbet or sorbet
  • sports drinks, such as gatorade or propel
  • gelatin

For a complete list of our office's acceptable clear liquids and to download, click here.

A laxative, type of bowel prep, is required the night before colonoscopy. This is medicine that loosens stool and increases bowel movements. It is usually a powder dissolved in water.

Patients should inform the doctor of all medical conditions and any medications, vitamins, or supplements taken regularly, including

  • aspirin
  • arthritis medications
  • blood thinners
  • diabetes medications
  • vitamins that contain iron or that thins blood (i.e. Vitamin E)

Driving is not permitted for 12-24 hours after colonoscopy to allow the sedative time to wear off. Before the appointment, patients should make plans for a ride home.

How is colonoscopy performed?

Examination of the Large Intestine

During colonoscopy, patients lie on their left side on an examination table. In most cases, a light sedative, and possibly pain medication, helps keep patients relaxed. Deeper sedation may be required in some cases. The doctor and medical staff monitor vital signs and attempt to make patients as comfortable as possible.

The doctor inserts a long, flexible, lighted tube called a colonoscope, or scope, into the anus and slowly guides it through the rectum and into the colon. The scope inflates the large intestine with carbon dioxide gas to give the doctor a better view. A small camera mounted on the scope transmits a video image from inside the large intestine to a computer screen, allowing the doctor to carefully examine the intestinal lining. The doctor may ask the patient to move periodically so the scope can be adjusted for better viewing.

Once the scope has reached the opening to the small intestine, it is slowly withdrawn and the lining of the large intestine is carefully examined again. Bleeding and puncture of the large intestine are possible but uncommon complications of colonoscopy.

Removal of Polyps and Biopsy

A doctor can remove growths, called polyps, during colonoscopy and later send test them to a laboratory to test them for signs of cancer. Polyps are common in adults and are usually harmless. However, most colorectal cancer begins as a polyp, so removing polyps early is an effective way to prevent cancer.

The doctor can also take samples from abnormal-looking tissues during colonoscopy. The procedure, called a biopsy, allows the lab to look at the tissue with a microscope for signs of disease.

The doctor removes polyps and takes biopsy tissue using tiny tools passed through the scope. If bleeding occurs, the doctor can usually stop it with an electrical probe or special medications passed through the scope. Tissue removal and the treatments to stop bleeding are usually painless.

Helpful Tips for Colon Preps

So you are finally going to have that Colonoscopy! Always call our office with any questions you may have about your Colon Prep, but here are some helpful tips to make preparing a little easier:

Make certain you have plenty of clear liquids from the Clear Liquid List! Have enough broth and sport drinks
on hand, since that is the bulk of your nutrition for the day. While juices and water are excellent, they provide empty calories. Remember, you will be on LIQUIDS all day with NO SOLID FOOD. In this case, “more is better” with clear liquids! Since colon preps can affect our body’s electrolytes, if you don’t take enough clear liquids, you may feel weak or nauseated when drinking the Prep.

So you hate the taste of those Preps- most of us do! Don’t worry, drink it through a straw! It actually helps to bypass our taste buds. This works as an excellent way to drink anything we don’t like much! Some patients find taking sips of a favorite clear liquid in between cleanses the palate also.

Lastly, a “can-do”, positive attitude can get us through anything! By having your colonoscopy, you are taking a positive step in guarding your good health. When you are all finished, you will certainly feel a sense of accomplishment! Be proud of yourself!


Colonoscopy usually takes 30 to 60 minutes. Cramping or bloating from the inflated gas may occur during the first hour or so after the procedure. The sedative takes time to completely wear off. You may need to remain at the office for 1 to 2 hours after the procedure. Full recovery is expected by the next day. Eating lightly and avoiding alcohol the "day of" is recommended, but you may resume your normal diet and activities the next day. Having "soft stools" for a day or two afterwards is not unusual. Discharge instructions should be carefully read and followed.

Patients who develop any of these rare side effects should contact their doctor immediately:

  • severe abdominal pain
  • fever
  • bloody bowel movements
  • dizziness
  • weakness
  • Black or tarry stools
  • Nausea

At what age should routine colonoscopy begin?

Routine colonoscopy to look for early signs of cancer should begin at age 50 for most people—earlier if there is a family history of colorectal cancer, a personal history of inflammatory bowel disease, or other risk factors. The doctor can advise patients about how often to get a colonoscopy.


Common Colon  & Rectal Problems

Acceptable Clear Liquid Diet

The day before your procedure:

  • chicken broth only - no noodles
  • wonton broth only - strained!
  • apple juice
  • Gingerale
  • 7-UP / sprite
  • white grape juice
  • white cranberry juice
  • any dye free fitness water
  • seltzer-flavored OK
  • coffee / tea without milk or creamers!
  • ice pops (except red, purple, or blue colored)
  • gatorade (excepted red, purple, or blue colored)
  • jello (except red, purple, or blue colored)
  • water - flavored OK
  • *OK to mix & match - Have as much as you want if you're feeling hungry - More is better don't skimp!
  • Also ok to have before, during & after prep until midnight **


Content provided by National Digestive Disease Information Clearinghouse

Stop Colon Cancer Now!

The Affordable Care Act and Colonoscopy

Stop Colon Cancer Now

Colonoscopy For Dummies

Colonoscopy for Dummies
Download FREE at