When should I start colonoscopies?
Last updated September 3, 2026.
At 45 for average-risk adults, per the CDC - the start moved down from 50 as younger-onset cases rose. And screening is not automatically a colonoscopy: home stool tests (FIT or FIT-DNA) on shorter cycles are real options, with colonoscopy on a ten-year cycle when clean - its edge being detection plus polyp removal in one session, which is why screening can prevent colorectal cancer, not only find it. Start earlier with a close relative's colorectal cancer or advanced polyps (from 40, or ten years before their diagnosis age), inflammatory bowel disease, or known genetic risk. Symptoms at any age - blood in stool, lasting bowel changes, unexplained weight loss - mean a diagnostic look now. Modern preps are kinder than their reputation. Pymander is a free AI doctor, 24/7 by text, and can help you pick the test.
What to do
- 45? Put screening on the calendar: several test types qualify.
- Squeamish about scopes? Ask about home stool tests.
- Family history? Start at 40 or earlier: tell your doctor the details.
- Blood in stool or lasting change? Skip the schedule: that is diagnostic, now.
Related questions
- What screenings do I need at 50?
- When should I start mammograms?
- What does high blood sugar mean?
- What is preventive care?