What Is Colorectal Cancer Screening?
A screening test is used to look for a disease when a person doesn’t have symptoms. (When a person has symptoms, diagnostic tests are used to find out the cause of the symptoms.)
Colorectal cancer almost always develops from precancerous polyps (abnormal growths) in the colon or rectum. Screening tests can find precancerous polyps, so that they can be removed before they turn into cancer. Screening tests can also find colorectal cancer early, when treatment works best.
Regular screening, beginning at age 50, is the key to preventing colorectal cancer. The U.S. Preventive Services Task Force (USPSTF)recommends screening for colorectal cancer using high-sensitivity fecal occult blood testing, sigmoidoscopy, or colonoscopy beginning at age 50 years and continuing until age 75 years.
When Should I Begin to Get Screened?
- You or a close relative have had colorectal polyps or colorectal cancer.
- You have Inflammatory bowel disease, Crohn’s disease, or ulcerative colitis.
- You have genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).
Speak with your doctor about when you should begin screening and how often you should be tested.
Free or Low-Cost Screening
Where feasible, the 25 states and 4 tribes in CDC’s Colorectal Cancer Control Program provide colorectal cancer screening and follow-up care to low-income men and women aged 50–64 years who are underinsured or uninsured for screening, when resources are available and there is no other payment option.
Colorectal cancer screening tests may be covered by your health insurance policy without a deductible or co-pay.
Questions to Ask Your Doctor
Screening for colorectal cancer is recommended for men and women beginning at age 50. U.S. Preventive Services Task Force (USPSTF) guidelines for colorectal cancer screening include the following tests—
- Colonoscopy (once every 10 years).
- High-sensitivity fecal occult blood test, also known as a stool test (once a year).
- Flexible sigmoidoscopy (every 5 years with FOBT every 3 years).
The benefits and risks of these screening methods vary. Discuss with your doctor [PDF-178KB] which test is best for you, and check with your insurance provider to find out which tests are covered by your insurance plan, and how much you will have to pay. Medicare helps pay for colorectal cancer screening.
Do I need to get a screening test for colorectal cancer?
- What screening test(s) do you recommend for me?
- How do I prepare? Do I need to change my diet or my usual medication schedule?
- What’s involved in the test? Will it be uncomfortable or painful?
- Is there any risk involved?
- When and from whom will I get results?
If you’re having a colonoscopy or sigmoidoscopy, you will want to know—
- Who will do the exam?
- Will I need someone with me?
Some people are at increased risk because they have inflammatory bowel disease, a personal or family history of colorectal polyps or colorectal cancer, or genetic syndromes like familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (also known as Lynch syndrome). These people may need to start screening earlier than age 50. If you believe you are at increased risk, ask your doctor if you should begin screening earlier than age 50.
Tell your doctor if you have any of these symptoms—
- Blood in or on your stool (bowel movement).
- Stomach pain, aches, or cramps that do not go away.
- Losing weight and you don’t know why.
These symptoms may be caused by something other than cancer, but the only way to know what is causing them is to speak with your doctor about them.
Colorectal Cancer Screening Guidelines
Regular screening, beginning at age 50, is the key to preventing colorectal cancer.1 The U.S. Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer using high-sensitivity fecal occult blood testing, sigmoidoscopy, or colonoscopy beginning at age 50 years and continuing until age 75 years.1
People at higher risk of developing colorectal cancer should begin screening at a younger age, and may need to be tested more frequently. The decision to be screened after age 75 should be made on an individual basis. If you are older than 75, ask your doctor if you should be screened. For more information, read the current colorectal cancer screening guidelines from the USPSTF.
Recommended screening tests and intervals2 are—
- High-sensitivity fecal occult blood test (FOBT), which checks for hidden blood in three consecutive stool samples; should be done every year.
- Flexible sigmoidoscopy, where physicians use a flexible, lighted tube (sigmoidoscope) to look at the interior walls of the rectum and part of the colon; should be done every five years with FOBT every three years.
- Colonoscopy, where physicians use a flexible, lighted tube (colonoscope) to look at the interior walls of the rectum and the entire colon; should be done every 10 years. During this procedure, samples of tissue may be collected for closer examination, or polyps may be removed. Colonoscopies can be used as screening tests or as follow-up diagnostic tools when the results of another screening test are positive.
- Colonoscopy also is used as a diagnostic test when a person has symptoms, and it can be used as a follow-up test when the results of another colorectal cancer screening test are unclear or abnormal.
RELATED LINK | Colorectal Cancer Screening Saves Lives brochure
RELATED LINK | Colorectal Cancer Screening: Basic Fact Sheet
Information from the Centers for Disease Control and Prevention