US Trends

colonoscopy what age

Most people should start regular colonoscopy screening at age 45 if they are at average risk for colorectal cancer, and continue until about age 75, with the exact schedule decided with their doctor.

Key ages at a glance

  • Start for most people (average risk): 45 years old.
  • Routine screening window: 45–75 years old, with colonoscopy typically every 10 years if results are normal (other test options may have shorter intervals).
  • Ages 76–85: Screening becomes an individual decision based on overall health, prior test results, and life expectancy.
  • After 85: Screening is generally stopped.

Think of it like a long-term safety check: from your mid‑40s through mid‑70s, your bowels get a scheduled “inspection” so small polyps can be removed before they ever turn into cancer.

When to start earlier than 45

You may need colonoscopy (or other colorectal screening) before 45 if you are higher risk. Examples include:

  • A close relative (parent, sibling, child) with colorectal cancer or advanced polyps, especially at a young age.
  • Personal history of polyps or colorectal cancer.
  • Chronic inflammatory bowel disease (Crohn’s disease or ulcerative colitis).
  • Certain inherited syndromes (like familial adenomatous polyposis or Lynch syndrome).

In these cases, doctors may recommend starting around 40 years , or 10 years earlier than the age at which your close relative was diagnosed, whichever comes first.

Why the age moved from 50 to 45

For years, 50 was the usual start age, but major organizations lowered it because colorectal cancer has been rising in people under 50.

  • The U.S. Preventive Services Task Force now recommends starting at 45 (instead of 50).
  • The American Cancer Society and other groups have aligned with 45 as well.
  • Early‑onset colorectal cancer (diagnosed under age 50) has become a growing concern, making earlier screening more valuable.

Some experts are even debating if we should eventually start at 40, but there are cost and access concerns, so 45 remains the standard for average‑risk adults right now.

How often to get a colonoscopy

For someone average risk with a normal colonoscopy:

  • Colonoscopy: about every 10 years from 45–75.
  • Other options (like stool tests or CT colonography) have different intervals, but colonoscopy is often considered the “gold standard.”

If polyps are found, or if you’re high risk, your doctor may recommend repeating colonoscopy sooner (for example every 3–5 years) depending on what they see.

Simple rule of thumb

  • If you’re 45 or older and haven’t been screened: talk to your doctor about starting now.
  • If you’re younger than 45 but have family history or other risk factors: ask whether you should start early and how often you should be checked.

Bottom line: “Colonoscopy what age?” → For most people, start at 45 , keep going regularly until around 75 , and consider earlier or more frequent testing if your risk is higher.

Information gathered from public forums or data available on the internet and portrayed here.