American Board of Internal Medicine (ABIM) Certification Practice Exam

For patients with ulcerative colitis or Crohn's colitis, when should they begin surveillance colonoscopy?

1. After 5 years of disease

2. After 10 years of disease

3. After 8 to 10 years of disease

4. After 15 years of disease

The correct answer is: After 8 to 10 years of disease

For patients diagnosed with ulcerative colitis or Crohn's colitis, the recommendation for beginning surveillance colonoscopy is after 8 to 10 years of disease duration. This is due to the increased risk of colorectal cancer associated with long-standing inflammatory bowel disease. Specifically, guidelines suggest that individuals with ulcerative colitis, particularly those with pancolitis or left-sided colitis, start regular surveillance colonoscopy after 8 years from the onset of symptoms or diagnosis. In the case of Crohn's disease, the risk factors are more complex and can vary based on the location and extent of the disease, but also typically fall within the 8 to 10-year range for initiating surveillance. The rationale for this timing is that the risk of dysplasia and cancer significantly increases with prolonged inflammation in the colon. By starting surveillance at this interval, it allows for the early detection of dysplastic changes before they can progress to colorectal cancer, thereby improving patient outcomes. Surveillance colonoscopy is critical in this population to ensure timely intervention and management of any neoplastic changes that may arise due to the underlying disease process.