Jefferson University Hospitals

Colorectal Cancer Screening

What are Polyps?

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Polyps are an abnormal growth in the colon and are very common. In fact, one in three people over the age of 50 have polyps, and one in two people over age 60 have polyps. They can be flat or raised and range in size from a few millimeters – like a pencil eraser – to several centimeters.

Not all polyps are cancerous, but nearly all colorectal cancers begin as a polyp - which is why screening is recommended. All polyps that are removed during your colonoscopy are sent to a pathologist for closer examination under the microscope to see if they have any features that make them more worrisome. You should be notified of these results within two weeks.

Removal of precancerous polyps reduces the risk of getting colorectal cancer.

Ways to Screen for Colorectal Cancer

There are screening tests that can detect colorectal cancer and there are those that can both detect as well as prevent it. Tests such as:

Fecal Occult Blood Tests

Fecal occult blood tests check for tiny amounts of blood in three consecutive stool samples to look for polyps or cancer in the colon or rectum. If blood is detected, your doctor will recommend a colonoscopy to determine the source of the bleeding to diagnose and treat the condition. This test should be done every year.

Stool DNA

This is a test to look for cancer cells and tiny amounts of blood in the stool. One sample is collected and sent to a facility that does this testing. The frequency of this testing has not been established but probably should be done every three to five years. If the test is positive, your doctor will recommend a colonoscopy.


Sigmoidoscopy is a procedure that involves the insertion of a tube with a tiny camera on it while awake to obtain detailed images of the lower portion of your colon. It's used for colorectal cancer screening and to identify polyps, but can also help to identify the causes of diarrhea, abdominal pain, constipation, abnormal growths and bleeding. This is recommended every five years and if a polyp is found on sigmoidoscopy, your doctor will recommend a colonoscopy to visualize the entire colon.

About 1 in 3 adults (23 million) between 50 and 75 years of age is not being screened for colorectal cancer, according to the Centers for Disease Control and Prevention.


Colonoscopy is the gold standard for colorectal cancer screening. Why, you ask? The great advantage of a colonoscopy over other screening procedures is that if a suspect polyp is found, it can be removed immediately.

During a colonoscopy, a thin, flexible tube with a light and camera examines the colon. The procedure typically lasts 30 minutes under sedation. A colonoscopy is recommended every 10 years.

Is it time for your first (or next) colonoscopy? These recommended screening guidelines will help you decide:

  • If you are at the average risk of colorectal cancer, begin screening at age 50.
  • If you are African American, begin screening at age 45.
  • If you have a family history of colorectal cancer, you need to be screened using colonoscopy and start at age 40 or 10 years younger than the earliest diagnosis in your family.

If everyone 50 years old or older were screened regularly, as many as 60 percent of deaths from colorectal cancer could be avoided.

How often should colonoscopy be done?

  • Every 10 years if average risk
  • Every five years if colon cancer is in your family
  • Every three to five years for most people who have had polyps in the past

Learn About the Types of Colonoscopies Offered at Jefferson