Familial adenomatous polyposis (FAP) is an inherited condition in which numerous polyps (growths that protrude from mucous membranes) form on the inside walls of the colon and rectum. Having FAP makes it very likely that a person will get colorectal cancer.

People with FAP can develop polyps in their 20s and 30s or even earlier. They may have hundreds of polyps throughout the colon by their 30s. Surgery to remove the colon (colectomy) is usually the recommended treatment.

The gene mutation that causes FAP can be detected by a genetic screening blood test. If the test result is positive, immediate family members should also be screened. Yearly screening may need to begin as early as age 10.