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.

Nov. 16, 2017
References
  1. AskMayoExpert. Cologuard (stool DNA) test. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2017.
  2. Sweetser S, et al. Multi-target stool DNA test: Is the future here? Current Gastroenterology Reports. 2016;18:30.
  3. Bibbins-Domingo K, et al. Screening for colorectal cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2016;23:2564.
  4. Cologuard. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/cdrh/devicesatfda/index.cfm?db=pma&id=320556. Accessed Aug. 30, 2017.
  5. Cotter TG, et al. Long-term follow-up of patients having false-positive multitarget stool DNA tests after negative screening colonoscopy: The LONG-HAUL cohort study. Cancer Epidemiology, Biomarkers and Prevention. 2017;26:614.
  6. Ahlquist DA (expert opinion). Mayo Clinic, Rochester, Minn. Aug. 31, 2017.