Colonoscopy
Screening For Colon Cancer And Polyps

Colonoscopy

Contents

• What Is A Colonoscopy?
• How Do I Prepare For A Colonoscopy?
• What Happens In The Procedure?
• Does A Colonoscopy Hurt?
• What Are The Risks?
• What Do The Results Mean?
• What Is A Virtual Colonoscopy?
• How Much Is A Colonoscopy?

colonscope tube
Colonoscope tube that is
inserted through the anus.

Other names:
Colonoscopy is also called a coloscopy.
Colon cancer is also called colorectal cancer.

What Is A Colonoscopy?

Colonoscopy is a diagnostic test that involves examining the large intestines using a flexible viewing tube inserted through the anus. It is used in cases of inflammatory bowel disease (IBD) and in screening for colon cancer. If colon polyps are discovered (small growths on the intestine wall), they will be snipped off and sent to a lab to see if they are precancerous or not. The procedure takes 20 minutes to an hour and the patient is awake, but heavily sedated.

Colonoscopy can also diagnose:
• The cause of rectal bleeding
• Ulcerative colitis and Crohn's disease, both types of IBD.

What Is The Difference Between Colonoscopy And Sigmoidoscopy?

The tests are similar, the only difference being which part of the colon is examined. With colonoscopy, the entire colon is investigated (1200 to 1500mm in length). With a sigmoidoscopy, only the first part of the colon (known as the distal portion, about 600mm in length) is examined. While colonoscopy is more accurate, a sigmoidoscopy can suffice as a regular screening tool because colon cancer survival rates only appear to improve when cancer is detected in the distal portion.

According to the American Cancer Society's Guidelines for the Early Detection of Cancer, both men and women should screen for signs of colon cancer and colon polyps after the age of 50. There are 3 recommended schedules, any one will suffice:

1. Sigmoidoscopy every 5 years. If the test is positive a colonoscopy should be done. Or
2. Colonoscopy every 10 years, or
3. Double-contrast barium enema every 5 years. If the test is positive a colonoscopy should be done.

For those with a family history of colon cancer, screening is recommended from the age 35 or 40 and every 5 years thereafter.

How Do I Prepare For A Colonoscopy?

To prepare for your test, you need to clean out your colon so that the doctors can view it more easily. To do this, your doctor may ask you to:

1. Follow a special diet a day before the test: You won't be able to eat any solids and drinks may be limited to clear liquids like water, broth, carbonated beverages and tea and coffee without milk. You will need to avoid drinking anything that is red, orange or brown in color because it may be mistaken for blood during the test. Typically you will be told not to eat or drink after midnight before your exam.
2. Laxatives: You may be prescribed a strong laxative in pill or liquid form to make you go to the toilet the day before and morning of the exam.
3. Enema kit: You may also be told to use an over the counter enema kit the night before the exam. This may give you diarrhea.
4. Medications: If you take medications for a condition such as a heart problem or diabetes, remind your doctor about this. You may need to adjust your dosages temporarily for a few days before your test. Aspirin products like ibuprofen should be avoided 10 days before your test to minimize the risk of bleeding if a polyp is removed.

What Happens In The Procedure?

You will need to remove all your clothes and wear a hospital gown. Some patients are given a pill to sedate them, others are put on an IV drip to give pain medications. You begin your test by lying on the examination table with your knees drawn towards the chest. The clinician will insert a scope called a colonoscope into your rectum. It will be gradually fed further and further into the colon. The colonoscope has a light and video camera attached and images of your colon will be transferred to a nearby monitor. Air is pumped through the scope to expand your colon, so that it can be viewed more easily. You may feel some cramping and the urge to pass a bowel movement (the laxatives will have emptied your bowels, so don't worry, nothing is left to come out). If polyps are discovered, or the doctor wants to take a sample of tissue for biopsy, other instruments can be inserted through the scope.

Does A Colonoscopy Hurt?

No, it does not hurt. The staff will do everything possible to help you relax and feel comfortable. Most patients report feeling 'out of it' because of the sedatives they receive and often say it’s over before they even realize it. Even though you are awake, you may not remember it very well.

After The Procedure

1. You can go home after the exam, but arrange for someone to drive you because it can take a day for the sedative to wear off.
2. If your doctor removed a polyp, you may be advised to follow a special diet temporarily.
3. You may pass gas for a few hours after the exam, this is normal. Walking can help relieve any build up.

What Are The Risks?

The risk of serious complications are very low (less than 1 percent). The most serious risk is that of gastrointestinal perforation (accidentally puncturing a hole in the colon), which is life threatening and needs immediate surgical repair. Less serious complications include the risk of dehydration caused by taking laxatives before the test. To avoid this, you should drink large quantities of water for a few days before your test.

When To Call A Doctor

The following are early signs of complications after a colonoscopy:

• Severe abdominal pain
• Fever or chills
• Bleeding from the anus (more than half a cup). You may notice some small amounts of blood in your feces with your first bowel movement after your test. This is normal. If you continue to pass blood or large clots, contact your doctor immediately.

What Do The Results Mean?

Negative Result
A negative result is where the doctor finds no abnormalities in your colon. You can wait another 10 years before repeating the exam.

Positive Result
A positive result is where polyps or abnormal colon tissue was discovered. Depending on the size and number of polyps found, you will need closer monitoring in the future.
1. If 1 or 2 polyps less than 1cm in size were discovered then a repeat exam in 5-10 years will be recommended (depending on your colon cancer risk factors).
2. If polyps are larger or in bigger quantities, or the polyps found have suspicious cells, a repeat exam in 3 to 5 years may be recommended.
3. If polyps are cancerous, a follow up in as little as 3 to 6 months may be necessary.

What Is A Virtual Colonoscopy?

Because many people dislike the unpleasant invasiveness of a colonoscopy, researchers developed an alternative called a virtual colonoscopy (CT colonoscopy). Basically it involves taking a CT scan of the colon from the outside, without the need to insert a colonoscope. A thin tube will be inserted into the rectum to pump gas into the colon to expand it so that better images can be taken, but it is not as invasive as the colonoscope. No sedation is necessary. While better at discovering large knobby polyps than the traditional colonoscopy, the CT colonoscopy is less effective at finding small flat ones. Furthermore, a virtual screening does not allow for the removal of polyps if they are found. In 2008 the U.S. Preventative Services Task Force decided not to support CT colonoscopy for screening of cancer anymore.

How Much Is A Colonoscopy?

Without insurance: The average cost for those who are uninsured is about $3,000. If a polyp is removed, expect to pay an additional $200-$300.
With insurance: Some insurance companies cover 100 percent of the cost, others only cover a portion of the cost. Even if your insurance covers the cost of the procedure, you may still be billed for anesthesiologist fees (about $300).

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For more health information, see the following:

• Vaccinations for women: List of recommended vaccines.

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