Diagnosis

Screening tests play a key role in detecting polyps before they become cancerous. These tests can also help find colorectal cancer in its early stages, when you have a good chance of recovery.

Screening methods include:

  • Colonoscopy, the most sensitive test for colorectal polyps and cancer. If polyps are found, your doctor may remove them immediately or take tissue samples (biopsies) for analysis.
  • Virtual colonoscopy (CT colonography), a minimally invasive test that uses a CT scan to view your colon. Virtual colonoscopy requires the same bowel preparation as a colonoscopy. If a polyp is found, you'll need a colonoscopy to have it removed.
  • Flexible sigmoidoscopy, in which a slender, lighted tube is inserted in your rectum to examine it and the last third of your colon (sigmoid) and rectum. If a polyp is found, you'll need a colonoscopy to have it removed.
  • Stool-based tests. This type of test works by checking for the presence of blood in the stool or assessing your stool DNA. If your stool test is positive you will need a colonoscopy.
Aug. 18, 2017
References
  1. Macrae FA. Approach to the patient with colonic polyps. http://www.uptodate.com/home. Accessed March 18, 2017.
  2. Colon polyps. National Institute of Diabetes and Digestive and Kidney Disease. https://www.niddk.nih.gov/health-information/digestive-diseases/colon-polyps. Accessed March 18, 2017.
  3. Colon polyps. American College of Gastroenterology. http://patients.gi.org/topics/colon-polyps/. Accessed March 18, 2017.
  4. Polyps of the colon and rectum. American Society of Colon and Rectal Surgeons. https://www.fascrs.org/patients/disease-condition/polyps-colon-and-rectum. Accessed March 18, 2017.
  5. Colorectal cancer: Screening. Rockville, Md.: U.S. Preventive Services Task Force. https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/colorectal-cancer-screening. Accessed April 5, 2017.
  6. Feldman M, et al. Colonic polyps and polyposis syndromes. In: Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 10th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed March 18, 2017.
  7. Niederhuber JE, et al., eds. Colorectal cancer. In: Abeloff's Clinical Oncology. 5th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2014. https://www.clinicalkey.com. Accessed March 18, 2017.
  8. Goldman L, et al., eds. Neoplasms of the small and large intestine. In: Goldman- Cecil Medicine. 25th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed March 18, 2017.
  9. AskMayoExpert. Colorectal polyp surveillance. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
  10. Brown A. Allscripts EPSi. Mayo Clinic, Rochester, Minn. Jan. 25, 2017.
  11. Rajan E (expert opinion). Mayo Clinic, Rochester, Minn. April 10, 2017.