Stool DNA test results may include:
Negative result. A test is considered negative if abnormal DNA changes common to colon cancer or precancerous polyps and signs of blood aren't found in the stool. Your doctor may recommend you repeat the test in three years.
Positive result. A test is considered positive if abnormal DNA changes common to colon cancer or precancerous polyps or signs of blood are found in the stool sample.
Your doctor may recommend additional testing — typically a colonoscopy to examine the inside of the colon to determine if cancer or polyps are present.
For every 20 people who undergo stool DNA testing, one or two will have a positive result, but no cancer or polyps will be found during a follow-up colonoscopy. In these instances, further testing is usually not recommended.