A colonoscopy reduces your risk of colorectal cancer by about what percent?

Answer: 69%. The 30-minute screening can also add years to your life by cutting your mortality rate in a major way. That’s because most colorectal cancers begin as polyps, which are painless, noncancerous growths that can develop into cancer over time. Early detection puts them on your doctor’s radar and allows for monitoring or removal long before they become a problem.