Colonoscopy

What is a Colonoscopy?

A colonoscopy is an exam that is used to look for changes in the large intestine (colon) and rectum. These changes include swollen, irritated tissues, polyps or cancer.

During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the doctor to view the inside of the entire colon. The scope — which is long enough to reach the entire length of your colon — contains a light and a tube (channel) that allows the doctor to pump air, carbon dioxide or water into your colon. The air or carbon dioxide inflates the colon, which provides a better view of the lining of the colon. If necessary, tissue samples (biopsies), polyps or other types of abnormal tissue can be removed through the scope.

A colonoscopy typically takes about 30 to 60 minutes.

Indications for Colonoscopy

• Investigate intestinal signs and symptoms. A colonoscopy can help your doctor explore possible causes of abdominal pain, rectal bleeding, chronic diarrhea and other intestinal problems.

• Screen for colon cancer. If you're age 45 or older and at average risk of colon cancer your doctor may recommend a colonoscopy every 10 years.

• If you have other risk factors, such as a family history of colon cancer, your doctor may recommend a colon screening before age 45 or less than 10 years.

• Look for more polyps. If you have had polyps before, your doctor may recommend a follow-up colonoscopy to look for and remove any additional polyps. This is done to reduce your risk of colon cancer.

• Treat an issue. Sometimes, a colonoscopy may be done for treatment purposes, such as placing a stent or removing an object in your colon.

Risks

A colonoscopy poses few risks. Rarely, complications of a colonoscopy may include:

• A reaction to the sedative used during the exam

• Bleeding from the site where a tissue sample (biopsy) was taken, or a polyp or other abnormal tissue was removed

• A tear in the colon or rectum wall (perforation)

Colonoscopy Preparation

Before a colonoscopy, you'll need to clean out (empty) your colon. Any residue in your colon may make it difficult for the doctor to get a good view of your colon and rectum during the exam.

To empty your colon, your doctor will ask you to:

• Follow a special diet the day before the exam. Typically, you won't be able to eat solid food the day before the exam. Drinks may be limited to clear liquids — plain water, tea and coffee without milk or cream, broth, and carbonated beverages. Avoid red liquids, which can be mistaken for blood during the colonoscopy. You may not be able to eat or drink anything after midnight the night before the exam.

• Take a laxative. Your doctor will usually recommend taking a prescription laxative, usually in a large volume in either pill form or liquid form. In most instances, you will be instructed to take the laxative the night before your colonoscopy, or you may be asked to use the laxative both the night before and the morning of the procedure.

• Adjust your medications. Remind your doctor of your medications at least a week before the exam — especially if you have diabetes, high blood pressure or heart problems or if you take medications or supplements that contain iron.

Also tell your doctor if you take aspirin or other medications that thin the blood, or heart medications that affect platelets. The doctor may need to adjust your dosages or have you stop taking these medications temporarily.

What to expect

During the procedure

During a colonoscopy, you will wear a gown. Sedation or anesthesia is usually recommended. In most cases, the sedative is combined with pain medication given intravenously to lessen any discomfort. You'll begin the exam positioned on your side with your knees drawn toward your chest. The doctor will insert a colonoscope into your rectum. When the scope is moved or air is introduced, you may feel stomach cramping or the urge to have a bowel movement.

After the procedure

After the exam, it takes about an hour to begin to recover from the sedative. You'll need someone to take you home because it can take up to a day for the full effects of the sedative to wear off. Don't drive or make important decisions for the rest of the day. You may feel bloated or pass gas for a few hours after the exam, as you clear the air from your colon. Walking may help relieve any discomfort.

You may notice a small amount of blood with your first bowel movement after the exam. Usually this isn't cause for alarm. Consult your doctor if you continue to pass blood or blood clots or if you have persistent abdominal pain or a fever. While unlikely, this may occur immediately or in the first few days after the procedure.

Results

You will have a one week follow up with your doctor to review the results of the colonoscopy and make recommendations for follow up.