WHAT IS A COLONOSCOPY? THE SIMPLE EXPLANATION

By: Manish Rungta, MD

Gastroenterology private practice with Bay Area Gastroenterology in Houston (Clear Lake), Texas

What is a screening exam?

Medical screening exams are commonly performed on healthy individuals to look for potential problems before they become serious. A common example is the Pap smear which is now a well accepted screening tool. If a Pap smear shows pre-cancerous cells, they can be destroyed and cancer is prevented. This simple procedure has reduced a woman's risk of cervical cancer significantly. The basic principle of screening is that it is much more rewarding to prevent a cancer than find one, even in early curable stages.

The same rule holds true for colon cancer. Most people don't realize that colon cancer has become the second leading cause of cancer deaths in this country, second only to lung cancer. In fact, in non-smokers, colon cancer is the number one cancer killer with over 56,000 Americans dying this year alone. That's the bad news. The good news is that colon cancer is also one of the most preventable. This is because the majority of colon cancers begin as small non-cancerous growths called polyps. Over time, polyps grow silently and eventually can turn to cancer. This transformation may take as long as ten years during which time you feel perfectly fine, unaware of the danger that awaits you.

How can I tell if I have polyps?

You can't. That is the problem. There are no symptoms of colon polyps and really no early warning symptoms of colon cancer. By the time a colon polyp turns into colon cancer and that cancer causes rectal bleeding or change in bowel habit, it has often already spread to the liver and other organs. This is why over 60% of cases are incurable at the time of diagnosis.

How can I reduce my risk of colon cancer?

The best way to avoid becoming a statistic is by beginning a program of regular screening exams. The most accurate screening test is a colonoscopy. This painless outpatient "scope" test is done under "twilight sleep" anesthesia and takes about 30 minutes. Most patients are pleasantly surprised by how simple it really is. The biggest complaint is the laxative preparation the night before, although there are easier alternative available now. But, if a polyp is detected during a screening colonoscopy, it can usually be removed at the same time, preventing a future colon cancer.

What other options are available?

There are other options available. All of them have the disadvantage of limited accuracy. An annual stool Hemoccult test for hidden blood is often done. This has some significance if abnormal, but the Hemoccult stool test can miss up to 85% of colon polyps and 60% of colon cancers.

For this reason, it is often combined with a flexible sigmoidoscopy "short scope" test. This exam does a good job of visualizing the left side of the colon and rectum, but cannot examine the right side of the colon where over 40% of colon cancers develop. Another option is a barium enema x-ray of the colon, but again the accuracy is limited. Less than half of significant colon polyps are detected. Colonoscopy has the advantage of seeing the entire colon directly, making it the most accurate screening method. For this reason, American Cancer Society recommendations now include colonoscopy as a screening procedure.

Who should be screened?

Colon cancer is an equal opportunity disease. It affects all races and men and women about equally. Current guidelines suggest screening for all average-risk adults over the age of 50. If the exam is normal and there are no other risk factors, a re-exam at 10 year intervals is recommended. Medicare recipients over age 50 are eligible for a screening colonscopy every ten years if they have not had a colonoscopy within the past 10 years or a flexible sigmoidoscopy within the past 4 years. High risk individuals are screened more often. These would be those with symptoms, prior colon cancer or polyps, inflammatory bowel disease, prior breast or uterine cancer, and those with a family history of colon cancer or polyps.

Will my insurance cover this?

As of 2001, Medicare pays for a screening colonoscopy in patients 65 years and older. If you're younger than 65, most insurance plans cover colon cancer screening, check with your insurer.

How can I schedule a Screening Colonoscopy?

If you are a healthy adult over age 50 and have not had a full colonoscopy within 10 years or a flexible sigmoidoscopy within the past 4 years, a screening exam may be indicated. You should first discuss this with your family physician. If you wish to be contacted about an appointment, simply contact our office by phone 281-480-6264 or via our website - www.gibay.com.

The Simple Fact…

is that 1 in 17 Americans now develops colon cancer in their lifetime and the majority is in advanced stages when first diagnosed. This is especially sad because there is about a 10 year "grace period" before cancer cells develop and we have the technology to intercede; however, most individuals do not take advantage of it. We hear the same excuses every month from the many patients we diagnose with colon cancer. They were misinformed, embarrassed, too busy, or just afraid to call and schedule a screening exam; however, once they find out how easily they could have avoided colon cancer, there are many regrets. Don't be one of those individuals.

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