What are My Colon Cancer Screening Options?


Knowing your risk factors for Colorectal Cancer is an important first step in staying healthy. In our October blog, we provided an overview of the two key categories of risk factors for colorectal cancer. It is equally important to get regular screenings to reduce your risk of developing colorectal cancer. Understanding the different types of screenings is also key. Staying in touch with your doctor and gastroenterologist is vital for early detection so that any symptoms can be tracked with your full medical history.

If your doctor determines that you should get screened for Colorectal Cancer there are two main categories of tests, Cancer Detection tests, which are stool-based tests, and Cancer Prevention tests, which are visual exams of the colon and rectum. Cancer Detection/Stool based tests will check your stool (feces) for any sign of cancer. In general, these tests are less invasive, typically done at home, and can be easier, but they do need to be done with more frequency. Cancer Prevention/visual exams are done in a medical facility where doctors look at the colon and rectum structure and search for any abnormal areas. This is done with either a scope or with x-ray tests. While they are more invasive, they are much more efficient and effective and highly recommended by gastroenterologists.

Some of the most common Cancer Detection/Stool-based tests include:

- Fecal Immunochemical Test (FIT): This test looks for hidden blood in the stool. This test is designed to find large colorectal polyps that are often fragile and are damaged by the passage of the stool. The damaged polyps usually bleed into the colon or rectum, and while it can’t generally be seen by the naked eye a FIT test will determine any presence of blood. The FIT test is thought to be one of the easiest tests to take because it can be done at home, and you don’t have to fast before taking the test. That being said, you must conduct this test annually to ensure the most accurate results.

- Guaiac-based fecal occult blood test (gFOBT): This test finds hidden blood in the stool via a chemical reaction. This test works similarly to the FIT test, but there are some foods and drugs that can affect the results. Because of this, doctors recommend avoiding NSAIDs such as ibuprofen or aspirin, vitamin C, and other citrus fruits at least seven (7) days before testing. They also recommend avoiding red meats at least three (3) days before testing. These foods can trigger a false-positive result. We recommend talking to your doctor or gastroenterologist if you have any questions.

- Stool DNA Tests: This test looks for abnormal sections of DNA from polyps and hidden blood. Since polyps can often become cancerous, they often have DNA mutations or changes in their genes. These DNA mutations often wind up in the stool where tests can detect them. Doctors recommend having this test done every three (3) years at home.

- When completing an at-home test, you must carefully follow all the instructions in the kit. If you have any questions about using your at-home test, contact your doctor or gastroenterologist.

Remember, if any positive results are indicated with a stool-based test, a colonoscopy will likely be required as a follow-up to validate results and help determine any next steps.

Some of the most common Cancer Prevention/visual or structural exams include:

- Colonoscopy: This test looks at the entirety of the rectum and colon with a colonoscope. A colonoscope is a small tube with a camera at the end that allows doctors to view and biopsy the colon. Because of the doctor’s ability to both view and biopsy the colon as well as remove any polyps, this is considered the best approach in screening for colorectal cancer. Be aware that before a colonoscopy you will be required to do a “bowel prep” to ensure that nothing is in your colon or rectum before the test. During the test, most people are given a sedative to help you relax and be more comfortable. Because there are no nerve endings in the colon itself, a colonoscopy and any related biopsies are typically pain-free and tolerated quite well. Colonoscopies are very safe and highly effective procedures. We recommend that you talk through any concerns with your gastroenterologist.

- CT Colonography: This test, also known as a virtual colonoscopy, scans the colon and rectum for any abnormal areas. It is done via either x-ray or CT scan to create 3D models of an individual’s colon and rectum. While this test is less invasive than a regular colonoscopy, it also requires bowel prepping for the most accurate results. If any concerns are identified during this test, a colonoscopy may still be needed to more fully explore the colon.

- Flexible Sigmoidoscopy: This test is very similar to a colonoscopy except that doctors do not examine the entire colon. During this test, doctors can only see about half the colon. Because it allows for less visualization and controls, this test is not widely used to screen for colorectal cancer.


For those with digestive issues or with increased risk of colorectal cancer, it is essential to stay in touch with their Gastroenterologist to screen and reduce the risk of colorectal cancer. If you are looking for a trusted gastroenterologist in Dallas/Fort Worth area, call us at 1-800-425-3759 to find a DHAT board-certified gastroenterologist near you or check us out at https://www.dhat.com