For most adults, the US Preventive Services Task Force recommends bowel cancer screening from age 45 to 75 and considers the decision individual for ages 76 to 85 [1]. Colonoscopy is one of the methods, and if it is normal it is usually repeated every 10 years; a yearly stool test (FIT) is also a valid method [2]. If your father, mother, sister, brother or child had bowel cancer or an advanced polyp before age 60 (or two of them at any age), you should have a colonoscopy every 5 years starting at age 40 or 10 years before the age of the youngest affected relative, whichever is earlier [3].
Screening age for people at average risk
| Age | Recommendation | Source |
|---|---|---|
| 45 to 49 years | Screening is recommended | US Preventive Services Task Force [1] |
| 50 to 75 years | Screening for everyone | US Preventive Services Task Force (strongest recommendation) [1] |
| 76 to 85 years | Individual decision based on overall health, previous screening and the person's wishes | US Preventive Services Task Force [1] |
| Over 85 years | Screening is not recommended | US Multi-Society Task Force [4]; American Cancer Society [2] |
"Average risk" means that neither you nor your family has a history of bowel cancer, polyps, inflammatory bowel disease or an inherited condition such as Lynch syndrome [1]. National screening programmes differ between countries in the starting age and the test offered.
For physicians
Why was the starting age lowered to 45? Citing the rising disease burden in people under 50, the similar prevalence of advanced neoplasia at age 45 to 49 and at 50 to 59, and modelling studies, the USMSTF proposed starting screening at 45, although there is no study showing an effect of screening under 50 on incidence or mortality [4]. The American Cancer Society's 2026 report also shows that colorectal cancer mortality in people under 50 has risen by 1% a year since 2004 [5].
Trial evidence: in the NordICC trial, people aged 55 to 64 who were invited to a single screening colonoscopy (only 42% attended) had an 18% lower risk of colorectal cancer after 10 years (0.98% vs 1.20%); the reduction in colorectal cancer deaths was not significant in the intention-to-screen analysis (0.28% vs 0.31%) [6].
Screening methods and intervals
| Method | Interval |
|---|---|
| Faecal immunochemical test (FIT) | Yearly |
| High-sensitivity guaiac faecal occult blood test | Yearly |
| Multitarget stool DNA test | Every 3 years |
| Colonoscopy | Every 10 years |
| CT colonography (virtual colonoscopy) | Every 5 years |
| Flexible sigmoidoscopy | Every 5 years |
The US Multi-Society Task Force (USMSTF) considers colonoscopy every 10 years and yearly FIT the first-tier tests [3].
Family history and people at high risk
Based on the US Multi-Society Task Force recommendations [3]:
- If one first-degree relative (father, mother, sister, brother or child) had bowel cancer or an advanced polyp before age 60, or two first-degree relatives at any age: colonoscopy every 5 years, starting at age 40 or 10 years before the age at diagnosis of the youngest affected relative, whichever is earlier.
- If one first-degree relative was diagnosed at age 60 or later: average-risk screening methods can be started at age 40.
People with inherited syndromes such as Lynch syndrome or familial adenomatous polyposis, inflammatory bowel disease or a history of polyps are not covered by the average-risk recommendations and have a separate plan [1].
When should I call my doctor?
Screening is for people without symptoms. Bleeding from the back passage or blood in the stool at any age, even in young people, needs a full diagnostic assessment [3]. In the United States, the incidence of bowel cancer in adults aged 20 to 49 has risen slightly every year, and it is now the leading cause of cancer death under 50 [5]; this makes knowing the symptoms and earlier diagnosis more important.
Related questions
Can a stool test (FIT) replace colonoscopy?
A yearly stool test is one of the valid methods, but if it is positive you need a colonoscopy promptly [2].
If my colonoscopy was normal, when should I repeat it?
For most people, every 10 years [2].
Is colonoscopy dangerous?
Serious complications are rare. In a large study of 11,843 people, 15 had serious bleeding after polyp removal, and there were no perforations or deaths within 30 days [6].
My stool test was positive; what should I do?
You need a colonoscopy, and you should not put it off. Full explanation: My faecal occult blood test was positive; what should I do?
Related cancer types
Related questions
References
6 referencesShow all references, 6 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1
- 2
- 3
- 4Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer
- 5Colorectal cancer statistics, 2026
- 6Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death
This page is based on reputable scientific sources and was last updated on 28 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
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