Detecting Colon Cancer Screening Options in 2021

Janet Ellen Ursua, FNP, Cucamonga Valley Medical Group

By Janet Ursua, FNP

Lurking deep within the lumen of your colon, polyps could be forming. Left undetected, these same polyps that are benign today, can continue to grow and may become malignant.

Colon cancer is the second leading cause of cancer death in the United States, with an overall survival rate of 65%. Screening for this potentially deadly cancer is an important part of your annual physical examination. The American College of Physicians recommends routine screening of average risk adults beginning at 50 through 75 years of age.

Knowing your choices while assessing your risk needs to be discussed with your primary care provider. You will need early and more frequent colon cancer screening with a colonoscopy if you have an increased risk of colon cancer including:

  • Personal history of colon cancer or precancerous polyps,
  • A parent, sibling or child with colon cancer or carry a gene for a hereditary colon cancer syndrome, or
  • A history of inflammatory bowel disease such as ulcerative colitis or Crohn’s disease.

Screening tests are used only if you do not have bowel symptoms. If you have signs and symptoms of abdominal pain or change in bowel habits, bleeding, constipation or diarrhea, then other tests will be needed to address these concerns.

If you do not have bowel symptoms, consider the following questions to help you to choose the colon cancer screening test that is best for you.


During this exam, a long flexible tube is inserted into the rectum. A small video camera at the tip of the tube allows the specialist to detect changes or abnormalities inside the entire colon. This procedure is repeated every 10 years if no polyps are found and you do not have an increased risk of colon cancer.

Colonoscopy is the MOST SENSITIVE test currently available.

While a thorough cleansing of the colon is required before the test and sedation is necessary, you will need someone to drive you home. Rare complications may include bleeding, cramping or tear in colon wall.

Stool DNA test

The stool DNA test uses a sample of stool to test for cell changes that might indicate the presence of colon cancer while also looking for signs of blood. This test is repeated every three years.

A bowel cleansing is not needed, and the stool is collected at home. The DNA stool test is less sensitive than colonoscopy. If abnormalities are found, additional tests including colonoscopy will be necessary.

The test results may also suggest an abnormality when none is present.

Fecal occult blood test or fecal immunochemical test

These laboratory tests check stool samples for hidden occult blood. These tests are usually repeated annually.

Stool sample collection can be done at home or during your annual physical exam. Sedation is not necessary and there is no need to empty the colon ahead of time.

These tests fail to detect polyps and cancers and certain foods or medications might need to be avoided for several days before the tests.

If blood is detected, additional tests will be necessary. False positive findings may also occur.

Virtual colonoscopy (CT colonography)

During this procedure, a CT scan produces cross-sectional images of the abdominal organs allowing the detection of abnormalities in the colon taking about 10 minutes. To help create clear images, a small tube is placed inside your rectum to fill your colon with air or carbon dioxide.

This test is usually repeated every five years. A full bowel prep is necessary to cleanse the colon before the exam including dietary and medication changes.

Tissue samples cannot be taken during the procedure and follow up colonoscopy may be needed if an abnormality is detected. Radiation exposure may also be a concern and cramping with bloating might occur afterward.

Weighing your risks and choosing a colon cancer screening test may not be an easy decision but it is potentially lifesaving. The more thorough the test, the more likely it will detect cancer or precancerous polyps.

Ask yourself, will you feel best if you know you have chosen the most thorough screening test possible? Will you doubt the results if you choose a less sensitive test? While you might be hesitant to make this decision, any embarrassment or discomfort from colon cancer screening is momentary and early detection may save your life.

2021 is the time to commit to a screening schedule based on your personal risk factors. The earlier colon cancer is detected, the easier it is to treat.

Call and schedule an appointment today with your CVMG PCP to discuss what option is right for you.

For more information, visit

Tests to detect colorectal cancer and polyps. National Cancer Institute[es/colorectal/screening-fact-sheet

Colorectal (colon) cancer: What should I know about screening? Centers for Disease Control and Prevention.