Blood tests are the newest option for colorectal cancer early detection and they come with real questions: who they are for, what they can and can’t find, and what happens next. On September 30, 2026, Fight Colorectal Cancer hosted its first community town hall to talk through those questions in plain language.
Our panel:
- Anjee Davis, MPPA, CEO of Fight Colorectal Cancer
- Andi Dwyer, MPH, University of Colorado Cancer Center and Colorado School of Public Health, and a member of Fight CRC’s Medical Advisory Board
The conversation was hosted by Erin Verscheure, Patient Education Manager at Fight CRC. Below are the questions from attendees and our Instagram community, with answers summarized from the panel’s discussion.
This information is for general education and is not a substitute for medical advice. Talk with your healthcare provider about which screening option is right for you.
Your questions, answered
What blood based screening options are available?
For people at average risk, there are three main types of screening. Stool tests include FIT and stool DNA or RNA tests. Colonoscopy is the only test that both finds and removes polyps. Blood tests are the newest option, and there are now a couple of FDA-approved blood tests for colorectal cancer (SimpleScreen™ and Shield™). These options are for people at average risk who are 45+, not survivors, people with a family history of colorectal cancer or colorectal cancer polyps, or people with genetic conditions like Lynch Syndrome or FAP
How do the national guidelines differ, and why does it matter?
Three groups issue the main screening guidelines: the U.S. Preventive Services Task Force (USPSTF), the American Cancer Society (ACS), and the National Comprehensive Cancer Network (NCCN). USPSTF guidelines shape Medicare and Medicaid coverage, which in turn guide private insurance.
All three agree that people at average risk should start screening at 45, with 75 as the upper age in the guidelines. But they don’t line up perfectly, and ACS recently updated its guidelines. When they differ, insurers can choose which one to follow, so coverage can vary.
Is there an age requirement for blood tests?
The ACS, USPSTF, and NCCN guidelines all recommend that people at average risk start screening at 45. Some communities face a higher risk of colorectal cancer and start screening earlier. For example, the Alaska Native Tribal Health Consortium recommends that Alaska Native people begin screening at 40. Talk with your provider about when you should start and which tests are right for you at your age. Under the ACS guidelines, though, blood tests are a later step: they’re offered to people who decline or don’t complete a stool test or a colonoscopy. As with any non-invasive test, an abnormal result means you need a colonoscopy.
Do colorectal cancer blood tests and stool tests do the same thing?
Not quite. Both can find colorectal cancer, but stool tests can also find some changes in cells, and they’re getting better at finding early polyps, growths that can turn into cancer. Finding and removing polyps is how screening prevents cancer. Blood tests usually miss polyps, so for now they’re a tool for early detection, not prevention. Science is improving, and researchers are working to help with blood tests to catch cancer at earlier stages.
READ OUR BLOG on BLOOD TEST FOR MORE INFO
Isn’t a colonoscopy always the best choice?
If a colonoscopy is your first choice and you can get one, go for it. But many people face barriers like access, long wait times, comfort level, and logistics. In rural and medically underserved communities, at-home stool tests are helping people get screened who otherwise wouldn’t, and blood tests offer another option for people who won’t or can’t do a stool test or colonoscopy. There’s no one-size-fits-all, and many people switch tests over their lives as their insurance, access, and circumstances change.
What happens if my stool or blood test is positive?
You need a colonoscopy. It’s not optional. Screening is a two-step process, and it isn’t complete until a positive stool or blood test is followed by a colonoscopy, ideally within 90 days.
Will insurance cover that follow-up colonoscopy?
Yes. After years of advocacy, a colonoscopy following a positive stool or blood test is considered part of screening, not a diagnostic test. That means you shouldn’t face cost sharing for it.
Who shouldn’t use a colorectal cancer stool or blood test?
Stool and blood tests are only for people at average risk. That means no personal or family history of colorectal cancer or certain polyps, no inflammatory bowel disease, no hereditary syndromes like Lynch syndrome or familial adenomatous polyposis, and no symptoms. If any of these apply to you, a separate set of guidelines applies, and you’ll usually go straight to colonoscopy. Learn more about colorectal cancer risks and prevention. Take our QUIZ
Can a stool test miss something?
Yes. No test is 100% foolproof, not even a colonoscopy. Every test has some chance of a false positive or false negative, though the tests keep getting more accurate. If you see blood in your stool and your stool test comes back negative, talk with your provider. If something doesn’t feel right, follow up and advocate for yourself.
How often do I need to repeat screening?
It depends on the test:
| Test | How often |
| FIT (stool test) | Every year |
| Stool DNA or RNA test | Every 3 years |
| CT colonography | Every 5 years |
| Flexible sigmoidoscopy | Every 5 years |
| Colonoscopy | Every 10 years, or sooner if polyps are found |
No screening test is one and done. Each test works best when you repeat it on schedule. A FIT test, for example, loses much of its power if you skip years. If polyps are found during a colonoscopy, ask your provider when your next screening is due. Learn more about screening HERE.
What about CT colonography and flexible sigmoidoscopy?
They’re used less often, but they still have a place. Flexible sigmoidoscopy checks only the lower part of the colon and the rectum. It usually doesn’t need sedation and uses a lighter prep, so you can often drive yourself home, which can help in rural areas. CT colonography is a virtual exam: a CT scan takes pictures of the whole colon. You still do the full prep, but you don’t need sedation. It can be an option if you can’t have a colonoscopy or prefer not to be sedated. If either test finds something, you’ll need a colonoscopy. CT colonography can’t remove polyps, and flexible sigmoidoscopy can’t check the rest of the colon.
How could changes to health coverage affect screening?
Medicaid: Starting January 1, 2027, many adults on Medicaid will need to show their working, volunteering, or in school, and renew their coverage every 6 months. Losing coverage could make colorectal cancer screening harder to get. If you have Medicaid and you’re due, get screened now and respond to renewal notices quickly.
Medicare: Medicare covers colorectal cancer screening starting at 45, including a yearly stool test (FIT) and, as of June 2026, FDA-approved blood tests every 3 years. A follow-up colonoscopy after a positive stool test is covered with no cost sharing. If a polyp is removed during a screening colonoscopy, you may owe part of the cost, so ask your provider how it will be billed.
If I take the Fight CRC screening quiz, what will happen with my results?
You’ll see a short summary of your answers and where you fall. Fight CRC does not store individual-level data. The quiz doesn’t recommend a specific doctor, but you can use our Provider Finder if you need help finding one. Take the quiz: FightCRC.org/quiz.
The one thing Anjee & Andi want you to remember
Talk with your healthcare provider, understand what each test checks for, and choose one you can commit to. If your insurance changes, you can switch your screening option. But if you choose a noninvasive test and it’s positive, get a colonoscopy.
Free resources from Fight CRC
- Screening quiz: 13 questions, about one minute, to help you understand your risk and which tests may fit you. Easy to share with friends and family.
- ChatCRC: Ask questions anytime online or by text at 318-242-8272.
- Provider Finder: Find specialists experienced in colorectal cancer.
- Printed resources: Free, medically reviewed brochures and handouts, including in Spanish and Chinese.