Most major guidelines now say people at average risk should start colon cancer screening at age 45 , not 50 as used to be standard. Screening is typically repeated on a schedule until about age 75, depending on the test and your results.

When healthy adults should start

  • Average‑risk adults : First screening at 45 years old , regardless of sex.
  • Common stopping range : Routine screening usually continues until age 75 ; decisions between 76–85 are “individualized,” balancing risk, life expectancy, and comorbidities.

When to start even earlier

You may need earlier or more frequent screening if you have higher risk, such as:

  • A close relative (parent, sibling, child) who had colorectal cancer or advanced polyps, often prompting starting at 40 or earlier —or 10 years before the relative’s diagnosis age.
  • Inflammatory bowel disease (Crohn’s disease or ulcerative colitis): often start colonoscopy around 8 years after diagnosis , then repeat every 1–3 years.
  • Genetic syndromes like Lynch syndrome or familial adenomatous polyposis : screening usually begins in the 20s or even earlier , with frequent colonoscopies.

How often to repeat screening

Intervals depend on the test and whether anything concerning is found. Typical schedules for normal results include:

Test type| Typical interval
---|---
Colonoscopy| Every 10 years
Stool‑based FIT (fecal immunochemical test)| Every year
sDNA‑FIT (stool DNA test)| Every 1–3 years
CT colonography| Every 5 years
Flexible sigmoidoscopy| Every 5 years , or 10 years with yearly FIT

Quick “when‑to‑see‑doctor” checklist

See your doctor sooner than age 45 if you:

  • Have new or persistent bowel changes (change in stool caliber, unexplained diarrhea/constipation).
  • Notice rectal bleeding, black/tarry stools, significant unintended weight loss, fatigue, or abdominal pain.
  • Have the risk factors listed above or worry about family history.

For your own care, the bottom‑line is: “When to get screened for colon cancer” usually means 45 for average‑risk adults, earlier if you have family history or inflammatory bowel disease or genetic syndromes—and then repeating tests on the schedule your clinician tailors to you.

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