American Board of Internal Medicine (ABIM) Certification Practice Exam

How frequently should colonoscopy be performed for average-risk patients?

1. Every year

2. Every 5 years

3. Every 10 years

4. Every 15 years

The correct answer is: Every 10 years

For average-risk patients, colonoscopy is recommended every 10 years as a standard screening interval. This recommendation is based on guidelines from major health organizations, recognizing that this timeframe balances the benefits of early detection of colorectal cancer with the risks associated with the procedure, including potential complications. The rationale for the 10-year interval stems from the understanding of the natural history of colorectal cancer and adenomatous polyps. Studies show that colon polyps typically take several years to develop into cancer, which supports a longer screening interval for those who exhibit no risk factors. The yearly and 5-year intervals are generally reserved for individuals with higher risk factors, such as those with a family history of colorectal cancer or genetic predispositions, necessitating more frequent surveillance. Meanwhile, a 15-year interval is not supported as it may allow for undetected lesions to progress to cancer more than is considered acceptable for average-risk populations. Thus, the 10-year frequency strikes a balance that enhances patient safety and efficiency in cancer screening protocols.