Colonoscopy: screening for colorectal cancer

What is a colonoscopy?

A colonoscopy is a procedure through which a doctor can closely check the lining of the entire colon (large bowel). A flexible tube (about the thickness of your finger) is passed into the anus and advanced slowly into the rectum and colon.

What preparation is needed for this procedure?

The colon must be completely clean for the procedure. You will be given detailed instructions about the diet you should follow and about how to cleanse your bowel before the procedure. Be sure to remind your health care provider about:

  • The medications you take regularly. This is especially important if you take an anticoagulant ("blood thinner") or aspirin.
  • Any allergies you have.
  • If you take antibiotics before dental or other procedures.

What can you expect during the colonoscopy?

You will probably be given medication to help you relax. You should not feel pain, but you may feel pressure or cramping from the air that is put into your bowel through the tube. You will be lying on your side or on your back during the procedure, which usually takes 15 to 60 minutes.

What if something abnormal is found?

If an area needs to be looked at more closely, a biopsy (sample of the colon lining) may be taken and sent to a lab for further testing. If polyps are found (growths from the lining of the colon) they can be removed during colonoscopy and sent for further testing.

What can you expect after the test?

Your health care provider will explain the results to you. Any cramping or bloating you feel should disappear quickly when you pass gas. If you were given medications, you will be observed until the sedative effect wears off. Be sure to have someone there to drive you home. You will be told when you can eat and resume normal activities. You may have small amounts of bleeding from your rectum for several days.

Complications after colonoscopy are rare. Be sure to call your health care provider if you have severe abdominal pain, fever and chills, or more than small amounts of rectal bleeding

DISCLAIMER: The information presented in this site is intended for general information and educational purposes. It is not intended to replace the advice of your own physician. Contact your physician if you believe you have a health problem.