Colon Cancer Screening

What is Colon Cancer?

Colon cancer starts as a small “polyp” (like a skin-tag) inside a person’s colon wall. Over time, the polyp can grow into a colon cancer. This is a slow process. It can take many years to develop. We generally screen for polyps and colon cancer between the ages of 50 to 74 because that is when most people tend to develop them.

You may wish to explore this website to learn more.

The short video below helps to explain colon cancer:

There are two main ways to screen for colon cancer:

(i) a Fecal Immunochemical Test (FIT)

(ii) a Colonoscopy

Fecal Immunochemical Test (FIT):

This is a stool test that you can do in privacy of your own home. It tests for microscopic blood in your bowel movement (blood you cannot even see with your eyes). If there is an early cancer in your colon, it may be shedding off tiny amounts of blood, and this test can help detect it and prompt further investigation (by getting a colonoscopy). This is a quick, easy, and painless test.

There are some problems with this FIT test, though. It is not as accurate as a colonoscopy. It can miss about 20% of early colon cancers. However, if you do the test every two years, the accuracy is better and it picks up most most of the early cancers. The FIT is also not as good at picking up the polyps (the early growths that turn into colon cancers). Unfortunately, the FIT test can miss many of the early polyps.

Another problem with the FIT is that it cannot distinguish the source of the bleeding. For example, a bleeding hemorrhoid or even a bleeding stomach ulcer can cause the test to come back positive for blood.

For detailed information about the FIT test, check out this website.

The following video demonstrates how to do the FIT test at home:

Colonoscopy:

You may know of friends or family who have had colonoscopies. Basically, you take a strong laxative the day before the procedure to totally clean out your bowel. You then go into the hospital for the procedure (but you are in and out the same day). They give you medications to doze you off, so you do not remember or feel anything, and then they go up inside your bottom end with a scope (which is basically a small video camera on the end of thin a flexible hose). From there, the doctor can directly see inside your colon wall and can see if there are any cancers or polyps. If they see a polyp, they can remove it right then and there before it ever turns into a cancer.

The colonoscopy is a better test in that the doctor can actually directly see inside your colon. It is more accurate and can catch early polyps before they ever even turn into a cancer. However, it is much more invasive and it does carry a very tiny risk of complication of popping through the bowel wall and requiring an operation to fix it (about 1 in 1000 to 1 in 10,000).

WHAT TEST SHOULD YOU GET?

If you have a direct family history (parents, siblings, or children) of colon cancer or even polyps, then you should get a colonoscopy. Remember to ask your family if they have had colonoscopies, what were the results? Even if it was “normal”, did they have any polyps? If so, you will need a colonoscopy.

If you do not have a family history, then there is really no correct answer. Each test has its pros and cons, and it is whichever you prefer.