The colonoscopy is the most widely used screening tool for colon and rectal cancer (colorectal cancer, or CRC), the second leading cause of cancer death in the U.S.

Most colorectal cancers start as polyps (growths). While about 20 percent of adults 50 and older have polyps, most never become cancerous. During a colonoscopy, a physician examines the colon and rectum with a lighted scope to look for polyps on the colon wall. If she does find any, she can often remove them on the spot, making the colonoscopy both a screening tool and a preventive procedure.

Who Needs a Colonoscopy?
The U.S. Preventive Services Task Force (USPSTF), an independent panel of experts in prevention and evidence-based medicine, conducted an extensive analysis of the benefits and risks of CRC screening. Based on this analysis, the task force recommends that:

  • People who have no symptoms or are not at high risk begin screening for colorectal cancer at age 50 and stop at age 75 if they've consistently had negative screenings, with incremental colonoscopies every 10 years.
  • Patients with polyps or adenomas (a type of benign tumor) should continue to undergo colonoscopy as long as it makes sense, based on the patient's health and age. According to the National Cancer Institute, an estimated 10 to 24 percent of adenomas will progress to cancer.

The results of the long-term National Polyp Study confirms that conducting colonoscopy in high-risk patients and removing precancerous adenomas can reduce the risk of colorectal cancer and halve the number of deaths from this disease.

Speak to Your Physician
Only about one-third of insured Americans age 50 or older have had a colonoscopy. Many states cover colorectal screenings, as does the Affordable Healthcare Act. If you're due for a colonoscopy but haven't yet had one, speak to your physician about your options.


American Cancer Society. "Colorectal Cancer Early Detection." Web. 24 Jan 2013.

National Cancer Institute. "Colorectal Cancer Screening (PDQ®)." Web. 19 July 2012.

National Cancer Institute. "Colonoscopy Reduces Risk of Death from Colorectal Cancer in High-Risk Patients." Web. 19 March 2012.

de Jonge, Vincent, BSc, Sint Nicolaas, Jerome, BSc, van Baalen, Onno, MD, et al. "The Incidence of 30-Day Adverse Events After Colonoscopy Among Outpatients in the Netherlands." American Journal of Gastroenterology 107(6) (2012): 878-884. Web. 26 July 2012.

Medscape Medical News. "Colorectal Cancer Risk Tied More to Colonoscopy Factors Than Polyp Features." Web. 20 August 2012.

Marshall, John L., MD. "Keep Patients Out of My Office, Says CRC Doc." Medscape Medical News. Web. 13 September 2011.

Zauber, A.G., Lansdorp-Vogelaar, I., Knudsen, A.B., Wilschut, et al. "Evaluating Test Strategies for Colorectal Cancer Screening: A Decision Analysis for the U.S. Preventive Services Task Force." U.S. Preventive Services Task Force. Web. October 2008.