Key Takeaways
- Average-risk adults should begin colorectal cancer screening at age 45.
- Colonoscopy is the only test that both finds and removes precancerous polyps in one procedure.
- At-home FIT and stool DNA tests (such as Cologuard) are convenient, evidence-based options that must be repeated regularly.
- Blood-based tests are the easiest to complete but the least sensitive for polyps — best for people who won’t do other tests.
- Any positive stool or blood test must be followed by a colonoscopy to complete screening.
- The best screening test is the one you will complete and follow through on.
Colorectal cancer is the second-leading cause of cancer death in the United States, yet it is also one of the most preventable cancers. Screening can find colorectal cancer early, when treatment is often more effective. In some cases, screening can even stop cancer from developing by identifying and removing precancerous polyps before they become dangerous.
Despite these benefits, millions of eligible adults remain unscreened.
Part of the challenge is that many people don’t realize they have options. While colonoscopy has long been considered the gold standard, advances in science have introduced additional screening choices, including at-home stool tests and newly approved blood-based screening tests.
The most important thing to know is this:
- The best screening test is the one you complete—and follow through on.
- Whether you’re approaching age 45, caring for a loved one, or advocating for better health outcomes in your community, understanding the strengths and limitations of each screening option can help you make informed decisions.
Why Colorectal Cancer Screening Matters More Than Ever
Colorectal cancer is the second leading cause of cancer death in the United States, yet it is one of the most preventable and detectable cancers when caught early. According to the American Cancer Society, approximately 158,850 Americans will be diagnosed with colorectal cancer in 2026, and approximately 55,000 will die from the disease — deaths that screening can help prevent. [1]
For years, colorectal cancer was considered a disease of older adults. That understanding has shifted significantly. Researchers have documented a steady rise in colorectal cancer diagnoses among adults younger than 50, with incidence rates increasing approximately 2% per year since the mid-1990s. [1] In response to this trend, the U.S. Preventive Services Task Force (USPSTF) updated its recommendation in 2021, lowering the screening start age from 50 to 45 for average-risk adults. [4]
Most recently, in May 2026, the American Cancer Society released its first major update to its colorectal cancer screening guideline since 2018. The updated guideline reaffirms that average-risk adults should begin screening at age 45 and continue through age 75 for those in good health, and—reflecting the latest science—formally adds newer options, including a next-generation multi-target stool DNA test, a new multi-target stool RNA test, and a blood-based screening test. Even so, the ACS continues to recommend colonoscopy and high-sensitivity stool tests as the preferred methods, noting that blood-based tests are less likely to find precancerous growths and early-stage (Stage I) cancers and are therefore not a preferred option at this time. [1][2]
Who Should Get Screened?
Most adults at average risk should begin colorectal cancer screening at age 45 and continue through age 75, according to the American Cancer Society and the U.S. Preventive Services Task Force. People with a family history of colorectal cancer, inflammatory bowel disease, or a hereditary syndrome may need to start earlier or screen more often.
Average-Risk Adults
Current guidelines from the USPSTF, the American Cancer Society (ACS), and the National Comprehensive Cancer Network (NCCN) recommend that average-risk adults begin colorectal cancer screening at age 45. [3] You are generally considered average risk if you:
- Are between the ages of 45 and 75
- Have no personal history of colorectal cancer or adenomatous polyps
- Have no personal history of inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
- Have no known hereditary colorectal cancer syndrome, such as Lynch syndrome or familial adenomatous polyposis (FAP)
- Have no strong family history of colorectal cancer or polyps
Above-Average Risk — Talk to Your Doctor
Some individuals face a higher risk of developing colorectal cancer and may need to begin screening earlier, screen more frequently, or use specific screening methods. You may be at above-average risk if you have:
- A first-degree relative (parent, sibling, or child) diagnosed with colorectal cancer or advanced adenomas, particularly before age 60
- A personal history of adenomatous polyps (precancerous growths) found on a previous colonoscopy
- A personal history of colorectal cancer, even if previously treated
- A diagnosis of inflammatory bowel disease, including Crohn’s disease or ulcerative colitis
- A known or suspected hereditary syndrome such as Lynch syndrome (hereditary nonpolyposis colorectal cancer) or familial adenomatous polyposis (FAP)
Know the Warning Signs
While screening should not wait for symptoms, it is equally important to know what warning signs to watch for — because symptoms should never be ignored, regardless of your age or when you last had a screening test. Contact your healthcare provider promptly if you experience any of the following:
- Rectal bleeding or blood in the stool — which may appear bright red or make stool look dark and tarry
- A persistent change in bowel habits — including diarrhea, constipation, or a change in the consistency of your stool lasting more than a few days
- Narrow or pencil-thin stools — which can indicate a partial blockage in the colon or rectum
- Persistent abdominal discomfort — such as cramping, gas, bloating, or pain that does not resolve
- A feeling that the bowel does not empty completely after a bowel movement
- Unexplained weight loss — losing weight without trying or without a clear reason
- Unexplained fatigue or weakness — which can result from chronic blood loss or anemia associated with colorectal cancer
The Goal of Screening
Screening can:
✓ Detect cancer before symptoms appear
✓ Identify precancerous polyps
✓ Reduce the risk of developing colorectal cancer
✓ Lower colorectal cancer mortality
The challenge isn’t simply getting people screened—it’s ensuring they complete the entire screening process, especially when follow-up testing is needed.
Screening Option #1: Colonoscopy
A colonoscopy is the only colorectal screening test that can both find and remove precancerous polyps in a single procedure, which is why major guidelines consider it the gold standard. A normal result usually means you won’t need to screen again for 10 years.
The Gold Standard for Prevention
Colonoscopy remains the most comprehensive colorectal cancer screening method available.
Unlike other screening tests, colonoscopy allows physicians to both detect and remove precancerous polyps during the same procedure. This makes it the only screening option that actively prevents cancer while screening for it.
How Colonoscopy Works
During the procedure:
- A physician inserts a flexible scope through the rectum.
- The entire colon is examined.
- Polyps or suspicious tissue can be removed immediately.
- Tissue samples can be collected for further testing.
The procedure typically takes 30–60 minutes, though preparation and recovery require most of the day.
Pros and Cons of Colonoscopy
| Benefits | Limitations |
| Detects and removes polyps | Requires bowel preparation |
| Highest detection rates | Requires sedation |
| Only test that prevents cancer during screening | Requires a driver afterward |
| Longest screening interval | Time away from work or caregiving |
| Comprehensive evaluation | Small risk of complications |
Why Many People Choose Colonoscopy
A normal colonoscopy generally means you won’t need another screening for 10 years.
For many people, that long interval offsets the inconvenience of preparation and the procedure itself.
Public figures have helped chip away at the stigma, too. Actor Will Smith filmed his own colonoscopy to encourage people to get screened — a reminder that the prep is manageable and the peace of mind is well worth it.
Who May Benefit Most?
Colonoscopy may be particularly valuable for:
- Individuals with symptoms such as rectal bleeding
- People with a family history of colorectal cancer
- Patients who previously had polyps
- Anyone with a positive stool or blood screening test
- Those who prefer the most comprehensive screening approach
Read our Colonoscopy Prep Tips Blog.
Screening Option #2: At-Home Stool Tests
At-home stool tests — the fecal immunochemical test (FIT) and multi-target stool DNA tests such as Cologuard — detect signs of cancer in a sample you collect at home, with no bowel prep or sedation. They are effective and convenient but must be repeated regularly, and any positive result requires a follow-up colonoscopy.
For people who are average-risk prefer to avoid bowel preparation, sedation, or time off work, stool-based screening tests offer an evidence-based alternative.
These tests can be completed at home and mailed to a laboratory for analysis.
There are two primary categories:
1. Fecal Immunochemical Test (FIT)
FIT looks for hidden blood in the stool that may indicate colorectal cancer or advanced polyps.
Key Features
- Completed at home
- No dietary restrictions
- No bowel prep required
- Requires one stool sample
- Must be repeated every year
FIT at a Glance
| Feature | FIT |
| Collection | At home |
| Frequency | Annually |
| Detects Blood | Yes |
| Detects DNA Changes | No |
| Follow-Up Colonoscopy Needed if Positive? | Yes |
Advantages
- Affordable
- Easy to complete
- Widely available
- Supported by major screening guidelines
Limitations
- Less effective at detecting precancerous polyps
- Must be completed every year
- Positive results require colonoscopy
2. Multi-Target Stool DNA Tests
Multi-target stool DNA tests, including Cologuard, combine blood detection with molecular analysis of DNA changes associated with colorectal cancer.
How They Work
These tests examine:
- Blood in stool
- Abnormal DNA markers
- Molecular changes linked to cancer development
Key Features
| Feature | Stool DNA Test |
| Collection | At home |
| Frequency | Every 1–3 years |
| Detects Blood | Yes |
| Detects DNA Changes | Yes |
| Follow-Up Colonoscopy Needed if Positive? | Yes |
Advantages
- Higher cancer detection rates than FIT
- Convenient home collection
- No bowel preparation
- No sedation
Limitations
- More false-positive results than FIT
- Higher cost
- Less effective than colonoscopy for finding advanced precancerous lesions
The Most Important Rule About Stool Testing
A positive stool test is not a cancer diagnosis.
It is a signal that further evaluation is needed.
That evaluation must be a colonoscopy.
Unfortunately, many people never complete this critical follow-up step, reducing the life-saving benefits of screening.
Screening Option #3: Blood-Based Cancer Detection Tests
Blood-based screening tests look for cancer signals in a routine blood draw, making them the easiest option to complete. They are the least sensitive for precancerous polyps and early-stage cancer, so the 2026 American Cancer Society guideline recommends them mainly for people who will not complete a colonoscopy or stool test.
The Newest Option in Colorectal Cancer Detection
Blood-based cancer detection tests represent one of the most significant recent developments in cancer detection.
How Blood Tests Work
Blood-based screening tests look for:
- Circulating tumor DNA (ctDNA)
- Abnormal methylation patterns
- Cancer-associated biomarkers
These signals may indicate the presence of colorectal cancer.
Benefits of Blood Testing
- Simple blood draw
- Easy integration into annual physical exams
- May encourage screening among previously unscreened populations
- No special preparation required
Current Limitations
The biggest limitation is that current blood tests detect cancer rather than prevent it. While they can identify many existing cancers, they are significantly less effective at finding advanced precancerous lesions — a key reason the American Cancer Society’s 2026 guideline lists blood-based testing as a non-preferred option, recommended mainly for people who would not otherwise be screened. [1]
That means they may miss opportunities to stop cancer before it develops.
Blood Tests Compared
| Feature | Blood Test |
| Bowel Prep | No |
| Stool Collection | No |
| Sedation | No |
| Detects Existing Cancer | Yes |
| Detects Precancerous Polyps | Limited |
| Positive Result Requires Colonoscopy | Yes |
Who Might Consider Blood-Based Screening?
Blood tests may be particularly helpful for:
- Individuals who have declined other screening methods
- Patients facing logistical barriers
- People who are unlikely to complete stool testing or colonoscopy
- For someone who would otherwise remain unscreened, a blood test may provide an important opportunity to begin screening.
[Read our Guide to Cancer Screening Blood Tests]
Comparing Your Screening Options
Quick Comparison Chart for Average Risk Individuals
| Screening Method | Frequency | Home Test | Detects Polyps Well | Prevents Cancer Directly | Follow-Up Colonoscopy Required if Positive |
| Colonoscopy | Every 10 years | No | Excellent | Yes | N/A |
| FIT | Every year | Yes | Limited | No | Yes |
| Stool DNA Test | Every 1–3 years | Yes | Moderate | No | Yes |
| Blood Test | Every year | No | Limited | No | Yes |
It’s worth emphasizing that these options are not equivalent. Colonoscopy is the only test that both detects and removes precancerous polyps, so it can actually prevent cancer — not just find it. Stool and blood tests are valuable because they are convenient and non-invasive, which helps more people get screened in the first place. Under the 2026 ACS guideline, however, blood-based tests are recommended mainly for people who decline or have not completed a colonoscopy or stool-based test, and any positive result still requires a follow-up colonoscopy to complete the screening process. [1]
What Happens After a Positive Test?
Any positive stool or blood test must be followed by a colonoscopy. The initial test is only a signal; the colonoscopy confirms whether cancer or polyps are present and allows them to be removed. Screening is not complete until that follow-up colonoscopy is done.
This is where many people become confused.
Whether the positive result comes from:
- FIT
- Stool DNA testing
- Blood-based screening
…the next step is the same.
You Need a Colonoscopy
A follow-up colonoscopy is necessary to:
- Confirm findings
- Identify polyps
- Diagnose cancer if present
- Remove precancerous growths
Skipping the colonoscopy means the screening process is incomplete.
Think of the initial test as an alarm. The colonoscopy is what tells you whether there is truly a problem and allows action to be taken.
Choosing the Right Screening Test
The best colorectal cancer screening test is the one you will actually complete and follow through on. Colonoscopy is the most thorough, while stool and blood tests trade some sensitivity for convenience — but a positive result on any of them still requires a colonoscopy.
There is no universally perfect screening option.
The right choice depends on:
Your Preferences
- Do you want the most comprehensive test?
- Do you prefer an at-home option?
- Are you comfortable with bowel preparation?
Your Lifestyle
- Can you take a day off work?
- Do you have transportation support?
- Will you remember annual testing?
Your Medical History
- Personal history of polyps
- Family history of colorectal cancer
- Existing digestive conditions
- Previous screening results
The most effective screening strategy is the one that fits your circumstances and that you are willing to complete consistently.
Quick Summary
- Colorectal cancer screening should begin at age 45 for average-risk adults.
- Colonoscopy remains the only screening test that can both detect and remove precancerous polyps.
- FIT and stool DNA tests provide convenient at-home screening options.
- Blood-based screening tests offer a new, accessible alternative but currently detect fewer precancerous lesions.
- Any positive stool or blood test must be followed by a colonoscopy.
- The best screening test is the one you complete—and follow through on.
- Every completed screening represents an opportunity to detect cancer early or prevent it entirely.
- That’s why screening isn’t just a medical recommendation—it’s one of the most powerful tools we have to save lives.
Frequently Asked Questions
When should I start colorectal cancer screening?
Average-risk adults should begin colorectal cancer screening at age 45 and continue through age 75, according to the American Cancer Society and the U.S. Preventive Services Task Force. If you have a family history of colorectal cancer or other risk factors, talk to your doctor about starting earlier.
Is an at-home stool test as good as a colonoscopy?
Stool tests are effective at detecting cancer and are far better than no screening, but they are less sensitive than colonoscopy for precancerous polyps and must be repeated more often. A colonoscopy is the only test that can remove polyps during the exam, and any positive stool test must be followed by a colonoscopy.
How often do I need a colonoscopy?
For average-risk adults, a normal colonoscopy is repeated every 10 years. Your doctor may recommend a shorter interval if polyps are found or if you are at higher risk.
What is the best at-home colorectal cancer test?
The two main at-home options are the annual fecal immunochemical test (FIT) and the multi-target stool DNA test (such as Cologuard) every 1–3 years. The best one is the test you will complete on schedule; both require a follow-up colonoscopy if the result is positive.
Are blood tests for colon cancer accurate?
Blood-based tests can detect many existing cancers but are the least sensitive option for finding precancerous polyps and early-stage cancer. The 2026 American Cancer Society guideline recommends them mainly for people who decline or cannot complete a colonoscopy or stool test.
Does insurance cover colorectal cancer screening at 45?
Most health plans and Medicare cover recommended colorectal cancer screening for average-risk adults beginning at age 45, though specific coverage and follow-up costs vary. Check with your plan, and ask whether a follow-up colonoscopy after a positive stool or blood test is covered as part of screening.
What are the warning signs of colorectal cancer?
Common warning signs include rectal bleeding or blood in the stool, a lasting change in bowel habits, narrow stools, persistent abdominal discomfort, unexplained weight loss, and unexplained fatigue. See a healthcare provider promptly if you notice these — don’t wait for your next scheduled screening.
What happens if my screening test is positive?
A positive stool or blood test is not a cancer diagnosis; it is a signal that you need a colonoscopy to confirm the findings and remove any polyps. Screening is only complete once that follow-up colonoscopy is done.
ABOUT FIGHT COLORECTAL CANCER
Fight Colorectal Cancer (Fight CRC) is a leading patient-advocacy organization dedicated to ending colorectal cancer. We work alongside survivors, caregivers, researchers, and medical experts to fund research, advance policy, and educate the public about prevention, screening, and early detection. Our educational content is grounded in the latest evidence-based guidance from authorities such as the American Cancer Society and the U.S. Preventive Services Task Force — which is why patients, families, and clinicians trust us as a subject-matter resource on colorectal cancer screening.
Read more from our team: Prevention & Early Detection of Colorectal Cancer on LinkedIn.
References
[1] Wolf AMD, Hoffman RM, Walter LC, et al. Colorectal Cancer Screening: An Update to the American Cancer Society Guideline, 2026. CA: A Cancer Journal for Clinicians. May 27, 2026. doi:10.3322/caac.70083.
[2] American Cancer Society. American Cancer Society Updates Colorectal Cancer Screening Guideline (press release). May 27, 2026.
[3] American Cancer Society. Colorectal Cancer Screening Guidelines and Cancer Facts & Figures. Accessed 2026.
[4] U.S. Preventive Services Task Force. Colorectal Cancer: Screening. Final Recommendation Statement. 2021.
Disclaimer
This article is provided by Fight Colorectal Cancer for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your individual screening needs.
Fight CRC receives grants and sponsorships from organizations and companies involved in colorectal cancer screening. This article nevertheless reflects our own independent editorial views: our content is developed independently and is based on current clinical guidelines and evidence — it is not directed, reviewed, or approved by, and is not created on behalf of, any sponsor or screening partner.