March 16, 2018

4 Reasons Why a Colonoscopy is Better than a DNA Test (Cologuard)

General Health

In 2014, the U.S. Food and Drug Administration (FDA)  approved a non-invasive colorectal cancer screening test that can be done at home and mailed to a lab for analysis. The test, called Cologuard, looks for blood and DNA mutations in your stool that could indicate colorectal cancer.

For people who are afraid of having a colonoscopy, or who want to avoid the preparation before the procedure, Cologuard is another way to screen for colorectal cancer. However, a colonoscopy is still the best colorectal cancer screening test. Here are four reasons why:       

  • A colonoscopy examines your entire colon. During a colonoscopy, your doctor will visually examine your entire colon for colorectal cancer and colon polyps, or growths that can turn into cancer within 5-10 years if left untreated. Because the procedure is so thorough, it only needs to be repeated every 10 years. Stool tests do not allow for a visual examination of your colon and need to be repeated every three years.
  • A colonoscopy is the only test that screens for and prevents colorectal cancer. If your doctor finds a colon polyp during your colonoscopy, he or she can prevent it from turning into cancer by removing it. Although the Cologuard test can detect signs of colorectal cancer or advanced colon polyps, it can’t detect polyps in their earliest stages when they can be easily removed. If you receive a positive result on your Cologuard test, it is likely that you already have colorectal cancer or pre-cancerous colon polyps that are causing bleeding.
  • False positive results are common with non-colonoscopy screening tests. If you have another condition that could cause blood to show up in your stool, such as hemorrhoids, you could receive a false positive result on your Cologuard test.
  • You may still need a colonoscopy. If you receive a positive result on your Cologuard test, you will still need to have a colonoscopy to find out more about your condition. Cologuard is not appropriate for people who are at high risk of developing colorectal cancer or are already showing symptoms; if this applies to you, you will need to have a colonoscopy.

Although Cologuard can be used as an alternative test for people who refuse or are unable to have a colonoscopy, it has several drawbacks. When it comes to colorectal screening and prevention, a colonoscopy is still the best choice.

Fort HealthCare provides screening colonoscopies, and you can go home the same day that you have the procedure. Ask your primary care provider when a screening might be best for you.