For most people at average risk, a colonoscopy is recommended every 10 years starting at age 45. That schedule changes significantly if polyps are found, if you have a family history of colorectal cancer, or if you have certain health conditions. Your personal timeline depends on what category you fall into.
Average-Risk Screening: Every 10 Years
If you have no family history of colorectal cancer, no prior polyps, and no inflammatory bowel disease, the standard recommendation is straightforward: get your first colonoscopy at 45 and repeat it every 10 years. This applies to both men and women.
The starting age used to be 50. The American Cancer Society lowered it to 45 in 2018 after data showed rising rates of colorectal cancer in younger adults. The U.S. Preventive Services Task Force followed with the same recommendation in 2021. If you’re between 45 and 50 and haven’t been screened, you’re not too early. You’re on schedule.
After Polyps Are Found
A clean colonoscopy earns you 10 years before the next one. But if your doctor removes polyps, the clock resets to a shorter interval based on what was found. Not all polyps carry the same risk. Small, common types are far less concerning than larger or more unusual growths.
If 1 to 2 small tubular adenomas (the most common type of precancerous polyp) are completely removed during a high-quality exam, the current recommendation is to repeat your colonoscopy in 7 to 10 years. That’s a relatively reassuring finding. If more polyps are found, if they’re larger than 10 mm, or if they show certain cell patterns under the microscope, the interval shortens to 3 to 5 years. A type of flat polyp that contains abnormal cells calls for a repeat in 3 years.
Your gastroenterologist will tell you exactly when to come back based on the pathology report. This is one area where the specific details matter, so ask for a clear answer before you leave.
Family History Changes the Timeline
A close relative with colorectal cancer, particularly a parent, sibling, or child, moves your screening earlier and more frequently. The specifics depend on how many relatives were affected and how old they were at diagnosis.
- One first-degree relative diagnosed before age 60, or two or more first-degree relatives at any age: Start colonoscopy at age 40, or 10 years before your relative’s diagnosis, whichever comes first. Repeat every 5 years.
- One first-degree relative diagnosed at age 60 or older: Start at age 40 to 50. You can generally follow average-risk intervals of every 5 to 10 years after that.
- One first-degree relative with an advanced precancerous polyp: Start at 50 or at the age they were diagnosed, whichever is earlier. Repeat every 5 to 10 years.
These recommendations come from multiple major gastroenterology organizations and are largely consistent across guidelines. If colorectal cancer runs in your family, bring up screening with your doctor well before age 45.
Inflammatory Bowel Disease
People with ulcerative colitis or Crohn’s disease affecting the colon face a higher risk of colorectal cancer that increases over time. The initial screening colonoscopy for dysplasia (precancerous cell changes) should happen 8 to 10 years after the disease was first diagnosed, regardless of age. After that, ongoing surveillance colonoscopies are performed at shorter intervals, with the exact frequency tailored to what’s found on each exam.
If you also have a liver condition called primary sclerosing cholangitis, which sometimes accompanies IBD, surveillance should begin immediately at the time of that diagnosis rather than waiting 8 to 10 years.
Lynch Syndrome and Genetic Conditions
Lynch syndrome is an inherited condition that dramatically increases the risk of colorectal cancer, often at younger ages. People with Lynch syndrome need colonoscopies every 1 to 2 years, a far more aggressive schedule than any other group. If you’ve been diagnosed with Lynch syndrome through genetic testing or if multiple relatives on the same side of your family have had colorectal, uterine, or ovarian cancers at young ages, this accelerated schedule is essential.
When Screening Typically Stops
For most people, the decision to continue or stop screening becomes individualized after age 75. The benefits of finding early cancer need to be weighed against overall health, life expectancy, and the risks of the procedure itself. Someone in excellent health at 78 may still benefit from screening. Someone with multiple serious health conditions at 76 may not. There’s no hard cutoff, but routine screening for average-risk adults is generally not recommended after age 85.
Stool Tests as an Alternative
Colonoscopy isn’t the only way to screen for colorectal cancer. If you prefer a less invasive option, two stool-based tests are widely recommended, though they require more frequent use.
- FIT (fecal immunochemical test): Done at home once a year. It detects hidden blood in your stool.
- FIT-DNA (sold as Cologuard): A more comprehensive at-home stool test done every 3 years. It checks for both blood and DNA markers associated with cancer.
The tradeoff is clear: colonoscopy is more thorough and only needed every 10 years, but requires sedation and a day of bowel prep. Stool tests are simple but must be repeated regularly, and any positive result still requires a follow-up colonoscopy. Both approaches are effective when done on schedule. The best screening test is the one you’ll actually complete.