The Basics: Overview
If you're age 45 to 75, get tested regularly for colorectal cancer. A special test (called a screening test) can help prevent colorectal cancer or find it early, when it may be easier to treat.
You may need to get tested before age 45 if colorectal cancer runs in your family. Talk with your doctor and ask about your risk for colorectal cancer.
How often should I get screened for colorectal cancer?
How often you need to get screened will depend on:
- Your risk for colorectal cancer
- Which screening test you choose
How do I decide which test to take?
There are different ways to test for colorectal cancer. Your doctor can help you decide which test you would prefer.
Before you talk with your doctor about which test to get, it can be helpful to think about your values and preferences. Answer these questions to find out which test you would prefer — then share the results with your doctor.
Together, you and your doctor can make a screening plan that’s right for you.
The Basics: What to Expect
What are the different kinds of tests?
Several different kinds of tests can be used to screen for colorectal cancer. The main types are:
- Stool-based tests
- Tests that look directly inside the colon and rectum
Stool tests are done at home. You collect a stool (poop) sample and send it to a lab for testing. Then the lab sends the results to your doctor.
Tests that look directly at your colon and rectum — like a colonoscopy — happen in a doctor's office or hospital. For these tests, you need to take a laxative to clean out your bowels before the appointment. You'll get anesthesia before the test, and you'll need someone to drive you home after the test.
Your doctor will tell you how to get ready for your test, including if you need to avoid certain foods beforehand. Learn more about colorectal cancer screening tests.
Does it hurt to get a colonoscopy?
Preparing for a colonoscopy can be unpleasant, but most people agree that the benefits to their health outweigh any discomfort. And getting anesthesia means you won’t have any pain or feel uncomfortable during the test.
The Basics: Colorectal Cancer
What is colorectal cancer?
Colorectal cancer is a cancer that develops in the colon or the rectum. The colon is the longest part of the large intestine. The rectum is the bottom part of the large intestine.
Like all cancers, colorectal cancer can spread to other parts of your body. Find out more about colorectal cancer.
The Basics: Am I at Risk?
Am I at risk for colorectal cancer?
The risk of developing colorectal cancer increases as you get older. That’s why screening is recommended for everyone ages 45 to 75.
Other risk factors are:
- Having certain types of polyps (growths) inside the colon
- Having a personal or family history of colorectal cancer
- Smoking cigarettes
- Being overweight or having obesity
- Not getting enough physical activity
- Drinking too much alcohol
- Having certain health conditions, like Crohn’s disease, that cause chronic (long-term) inflammation (ongoing irritation) of the small intestine and colon
Use this calculator with your doctor to find out your risk of colorectal cancer.
Take control — act early.
If you start getting screened at age 45, you have a good chance of preventing colorectal cancer or finding it when it can be treated more easily.
- If your doctor finds polyps inside your colon during the test, they can remove the polyps before they turn into cancer
- If your doctor finds cancer during the test, you can take steps to get treatment right away
Take Action: Get Tested
The best way to prevent colorectal cancer — or find it early — is to get tested starting at age 45.
Talk with your doctor about getting screened.
Use these questions to ask your doctor about colorectal cancer screening. Take them to your next checkup — you can print them out or pull them up on a smartphone or tablet.
What about cost?
Under the Affordable Care Act, health insurance plans must cover screening for colorectal cancer. Depending on your plan, you may be able to get screened at no cost to you. Check with your insurance company to find out more.
Medicare may also cover screening for colorectal cancer screening at no cost. If you have Medicare, find out about Medicare coverage for different colorectal cancer screening tests.
If you don’t have insurance, you may still be able to get free or low-cost colorectal cancer screening. To learn more, find a health center near you.
To learn more, check out these resources:
- Free preventive care covered by the Affordable Care Act
- How the Affordable Care Act protects you
- Understanding your health insurance and how to use it [PDF - 698 KB]
If you're nervous about getting a colorectal cancer test, get support:
- Ask a family member or friend to go with you when you talk to the doctor
- Talk with people you know who have been screened to learn what to expect
Do you know someone age 45 or older who hasn’t been tested for colorectal cancer yet? Use these tips to start a conversation about the importance of screening.
Take Action: Healthy Habits
People who smoke are more likely to get colorectal cancer. If you smoke, make a plan to quit today.
Watch your weight.
Being overweight increases your chance of developing colon cancer. Find out how to control your weight.
Regular exercise may help reduce your risk of colorectal cancer. Take steps to get moving today.
Drink alcohol only in moderation.
Drinking too much alcohol may increase your risk of colorectal cancer. If you choose to drink, have only a moderate (limited) amount. This means:
- 1 drink or less in a day for women
- 2 drinks or less in a day for men
Talk with your doctor about taking aspirin every day.
Taking aspirin every day can lower your risk of colorectal cancer, heart attack, and stroke. But it’s not right for everyone. If you're age 50 to 59 and have risk factors for heart disease, ask your doctor if daily aspirin is right for you.
Content last updated June 10, 2021
This information on colorectal cancer was adapted from materials from the Centers for Disease Control and Prevention and the National Cancer Institute.
Rebecca Chasan, Ph.D.
Chief, Science Writing and Review Branch
Office of Communications and Public Liaison
National Cancer Institute
National Institutes of Health
Ann Pluta, Ph.D.
Scientific Communications Editor Office of Communications and Public Liaison
National Cancer Institute
National Institutes of Health