Colorectal Cancer Screening Tests

Screening is the process of looking for cancer in people who have no symptoms. Several tests can be used to screen for colorectal cancer. These tests can be divided into 2 main groups:

  • Stool-based tests: These tests check the stool (feces) for signs of cancer. These tests are less invasive and easier to have done, but they need to be done more often.
  • Visual (structural) exams: These tests look at the structure of the colon and rectum for any abnormal areas. This is done either with a scope (a tube-like instrument with a light and tiny video camera on the end) put into the rectum, or with special imaging (x-ray) tests.

These tests each have different pros and cons (see the table below), and some of them might be better options for you than others. But the most important thing is to get screened, no matter which test you choose.

If you choose to be screened with a test other than colonoscopy, any abnormal test result should be followed up with colonoscopy.

These tests, as well as others, can also be used when people have symptoms of colorectal cancer or other digestive diseases such as inflammatory bowel disease.

STOOL BASED TESTS

These tests look at the stool (feces) for possible signs of colorectal cancer (or polyps). Many people find these tests easier to have than tests like colonoscopy, and they are typically done at home. But these tests need to be done more often. And if the result from one of these stool tests is positive (abnormal), you’ll still need a colonoscopy to see if you have cancer.

What is F.I.T?

One way to test for colorectal cancer is to look for occult (hidden) blood in stool. The idea behind this type of test is that blood vessels in larger colorectal polyps or cancers are often fragile and easily damaged by the passage of stool. The damaged vessels usually bleed into the colon or rectum, but only rarely is there enough bleeding for blood to be seen in the stool.

The fecal immunochemical test (FIT) is also called an immunochemical fecal occult blood test (iFOBT). It tests for hidden blood in the stool.

This test reacts to part of the human hemoglobin protein, which is found in red blood cells.

For this test, small amounts of stool are collected on cards (or in tubes). You can do this in the privacy of your own home. Unlike the gFOBT (see below), there are no drug or dietary restrictions before the test (as vitamins and foods do not affect the FIT), and collecting the samples may be easier. This test is also less likely to react to bleeding from other parts of the digestive tract, such as the stomach.

Common Questions About F.I.T

How often must F.I.T. be done?

The FIT must be done every year.

If the FIT is positive for hidden blood, a colonoscopy(the gold standard) will be needed to investigate further.

Screening is the process of looking for cancer in people who have no symptoms.If you have any of the symptoms listed below(or in our information pamphlet),you should consult your health care provider.

What are the alternative names to F.I.T.?

Immunochemical fecal occult blood test; iFOBT; Colon cancer screening – FIT

How is the test performed?

You will be given the test to use at home. Be sure to follow the instructions provided. Most tests have the following steps:

  • Flush the toilet before having a bowel movement.
  • Put the used toilet paper in the waste bag provided. DO NOT put it into the toilet bowl.
  • Use the brush from the kit to brush the surface of the stool and then dip the brush into the toilet water.
  • Touch the brush on the space indicated on the test card.
  • Add the brush to the waste bag and throw it away.
  • Send the sample to the lab for testing.

Your doctor may ask you to test more than one stool sample before sending it in.

How to do I prepare for the test?

You do not need to do anything to prepare for the test.

How the test will feel?

Some people may be squeamish about collecting the sample. But you will not feel anything during the test.

Why the test is performed?

Blood in the stool may be an early sign of colon cancer. This test is performed to detect blood in the stool that you cannot see. This type of screening can detect problems that can be treated before cancer develops or spreads.

Talk with your doctor about when you should have colon screenings.

What are the common symptoms of colon cancer?
  • Change in bowel habits.
  • Blood on or in the stool.
  • Unexplained anemia.
  • Unusual stomach or gas pain.
  • Unexplained weight loss.
  • Fatigue.
  • Vomiting
What Abnormal Test Results mean?

If the FIT results come back positive for blood in the stool, your doctor will want to perform other tests, usually including a colonoscopy. The FIT test does not diagnose cancer. Screening tests such as a sigmoidoscopy or colonoscopy can also help detect cancer. Both the FIT test and other screenings can catch colon cancer early, when it is easier to treat.

What is a Normal Result?

A normal result means the test did not detect any blood in the stool. However, because cancers in the colon may not always bleed, you may need to do the test a few times to confirm that there is no blood in your stool.

What are the risks of F.I.T.?

There are no risks from using the FIT.