Besides colonoscopies done every 10 years, which tests are performed annually for colon cancer screening?

• A. FIT and FOBT
• B. Stool DNA test
• C. CT colonography
• D. Flexible sigmoidoscopy

Answer: (A)

Annual stool-based tests that look for hidden blood are options for colon cancer screening beyond a colonoscopy every 10 years. The correct choice includes two tests that are routinely done each year because they monitor for blood in the stool, which can be an early sign of polyps or cancer. The fecal immunochemical test (FIT) detects human blood in stool with antibodies, and the guaiac-based fecal occult blood test (FOBT) detects blood using a chemical reaction. Both are simple, typically done at home, and recommended annually because a negative result one year doesn’t guarantee there won’t be bleeding or a developing lesion the next year.

Other options aren’t annual: stool DNA testing is done less frequently (usually every 3 years), CT colonography is typically performed every 5 years, and flexible sigmoidoscopy is also done at longer intervals (around every 5 years). Colonoscopy remains the only test that is repeated every 10 years when results are normal. If any of these tests show abnormal results, a diagnostic colonoscopy is indicated.