What is a Colonoscopy?

Colonoscopy is a procedure in which a flexible tube is inserted into the rectum and slowly advanced until the entire colon (large intestine) has been examined.

Reasons for the Exam

Colonoscopy may be performed as a preventative screening test or to evaluate the following problems:

  • Rectal bleeding
  • Chronic diarrhea
  • Personal history or family history of colon polyps or cancer
  • Abnormal X-rays of the colon
  • Iron deficiancy anemia
  • Evaluation of inflammitory bowel disease

Different types of instruments can be passed through the colonoscope. Polyps (abnormal growths that are pre-cancerous) or cancers can be biopsed or removed, and in some instances, certain types of bleeding can be treated.


You will be given a special liquid diet and laxatives the day before the exam. No solid foods (jello is OK, except red jello) should be consumed the day before the exam and nothing after midnight. Your doctor may also wish you to discontinue aspirin or blood thinners for several days before the exam if he or she believes a biopsy might be required. To view the various preparation instructions click here.

What happens durning a Colonoscopy?

An IV will be started prior to the procedure and monitors will be connected so that your blood pressure and respiration can be monitored during the test. You will be lying on your left side to start the procedure although your position may be changed during the test to help advance the intrument aroung your colon. Medications will be given through your IV to sedate you and control any discomfort, although this procedure is generally well tolerated and rarely causes significant pain. The procedure takes 15-60 minutes to perform depending upon whether any polyps need to be removed during the procedure.

After the Exam

You will be monitored in the recovery area until most the side effects of the medications have worn off. This is usually about 30 to 60 minutes. You will expierence some bloating and/or cramping after the test due to the air placed in the colon. This will be relieved over time by natural passage of air. You will be able to resume your usual diet unless your doctor tells you otherwise.

Possible complications of Colonoscopy

Colonoscopy is a safe procedure. Although complications can occur, they are uncommon when the procedure is perfomed by a physician who has been specially trained. Doctors Roberts and King together have done many thousands of these procedures over more than 40 years. one possible complication is bleeding when a biopsy is performed or a ployp is removed. This usually stops on its on, or can be controlled through the colonoscope. Rarely, it will require blood transfusions or surgery. Another possible complication is perforation, which is a tear in the lining of the colon. This usually requires surgery or repair. Other potential risks include reactions to the sedatives used. One minor complication that can occur is irritation of the vein at the IV site. This not dangerous and usually goes away in a few weeks. Although colonoscopy is an accurate exam, it is not perfect. It is possible that rarely a tumor or cancer could be missed by the colonscopy. This is less likely to happen if the colon is clean. It is important that you follow the instruction for the prep closely.