Why it's done

Stool DNA testing is intended to screen for colon cancer or precancerous polyps in people with no symptoms.

The stool DNA test detects abnormal DNA and small amounts of blood shed into the stool from colon cancer or colon polyps.

When cancer or polyps are present in your colon, they continuously shed cells with abnormal DNA changes into the stool. The DNA changes are found in very tiny amounts, so very sensitive laboratory methods are required to detect them.

Research shows the stool DNA test is effective at detecting colon cancer and precancerous polyps. A positive test result usually requires a colonoscopy to examine the inside of your colon for polyps and cancer.