Regular screening is one of the most important aspects of cancer prevention, as pre-cancerous cells or early-stage cancers are much more treatable that their late-stage counterparts. It is recommended that those between the ages of 45 – 75 years old be screened for colorectal cancer on a regular basis. [1]

The first category of colorectal screening tests are stool tests. Two of these tests, the guaiac-based fecal occult blood test (gFOBT) and the fecal immunochemical test (FIT) look for the presence of blood in stool. The gFOBT test detects blood with the chemical guaiac, whereas the FIT test using antibodies to detect the blood. These tests are recommended on a yearly basis. The third kind of stool test is the FIT-DNA test, which is like a regular FIT test except it also tests the stool sample for mutated DNA that could be indicative of cancer. This test is recommended to be done every three years. [1]

The next category of colorectal screening tests includes the flexible sigmoidoscopy, the colonoscopy, and the CT colonography/virtual colonoscopy. These tests tend to be done less often than stool test. The flexible sigmoidoscopy is a test where a thin, flexible metal tube is placed in the rectum, allowing the doctor to check the rectum and lower parts of the colon for polyps or cancer. This is done every five years to ten years, depending on if the patient is also doing stool testing. The colonoscopy, perhaps the most well-known of colorectal cancer screenings, is similar to a sigmoidoscopy, except the tube is longer, allowing the doctor to examine the entire length of the colon. A colonoscopy is recommended every ten years. A CT colonography/virtual colonoscopy is when x-rays and computer imaging is used to view the entire colon for polyps or cancer. This test is recommended every five years. [1]

It’s important to work with your doctor to come up with a colorectal cancer screening schedule for yourself and determine which tests you would like to use. When deciding on colorectal cancer screening, it is also important to consider such things as your current medical conditions and if you have a family history of colorectal cancer. [1]

References:

1.     Colorectal cancer screening tests. https://www.cdc.gov/cancer/colorectal/basic_info/screening/tests.htm (accessed Mar 1, 2022).