American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the guideline for regular screening for colon cancer in patients who decline a colonoscopy?

1. CT colonography every 10 years

2. Flexible sigmoidoscopy every 5-10 years

3. Magnetic resonance colonography every 5 years

4. All of the above

The correct answer is: Flexible sigmoidoscopy every 5-10 years

Regular screening for colon cancer is essential for early detection and prevention, especially in patients who are at average risk. When a patient declines a colonoscopy, alternative screening methods are available to ensure that they still receive appropriate surveillance for colorectal cancer. Flexible sigmoidoscopy is one of those viable alternatives. It allows for examination of the lower part of the colon and can be performed at intervals of every 5 to 10 years. This method is less invasive than a full colonoscopy and can be a suitable option for patients who are unwilling or unable to undergo the more comprehensive procedure. It’s important to note that flexible sigmoidoscopy does not visualize the entire colon, which is one of the limitations compared to a complete colonoscopy. While CT colonography is a non-invasive option, it typically has a recommended screening interval of every 5 years rather than every 10 years, which might result in it being less preferred when considering patient compliance and practical limitations. Magnetic resonance colonography, although an emerging modality, is not as widely endorsed or standardized for routine screening compared to flexible sigmoidoscopy. Thus, among the choices, flexible sigmoidoscopy every 5-10 years is the most widely accepted guideline for patients who decline colonoscopy, making