US Colonoscopy Screening Guidance Updated: Begin at Age 45, Repeat Every 10 Years

Colonoscopy remains the gold‑standard test for colorectal cancer screening. U.S. professional societies now advise that average‑risk adults start routine screening at age 45. If the initial exam is normal, a repeat colonoscopy is recommended roughly every ten years, though some guidelines suggest extending the interval to 15 years for low‑risk individuals with a clean result.

People with a first‑degree relative diagnosed with colorectal cancer before age 60, or those with multiple affected relatives, should begin screening at age 40 or ten years earlier than the youngest case in the family, whichever comes first. For adults over 75, continuation of screening depends on overall health, life expectancy, and personal preferences. The procedure allows immediate removal of polyps, which can lower colorectal cancer mortality by more than half. Risks are low but include bleeding, perforation, and infection.

Alternative screening methods such as fecal immunochemical tests (FIT) or multitarget stool DNA are available, but a positive result on any of these typically leads to a follow‑up colonoscopy for confirmation and possible treatment.