American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the first-line test for evaluating the small intestine in patients with obscure gastrointestinal bleeding?

1. Enteroscopy

2. CT enterography

3. Capsule endoscopy

4. Abdominal ultrasound

The correct answer is: Capsule endoscopy

Capsule endoscopy is the first-line test recommended for evaluating the small intestine in patients with obscure gastrointestinal bleeding. This technique involves swallowing a small, pill-sized camera that captures images of the intestinal tract as it passes through. It is particularly advantageous for assessing the small bowel because it provides a non-invasive means to visualize areas that may be challenging to reach with standard endoscopy or imaging techniques. Capsule endoscopy allows for thorough examination of the mucosal surface throughout the small intestine, enabling the detection of lesions, ulcers, and potential sources of bleeding that may not be visible through other modalities. Its ability to capture high-quality images from multiple angles facilitates the accurate diagnosis of obscure causes of gastrointestinal bleeding. While other tests such as enteroscopy, CT enterography, and abdominal ultrasound have their roles in gastrointestinal evaluation, they are not considered the first-line approach for this specific indication. For instance, enteroscopy is more invasive and is often used after capsule endoscopy in cases where further intervention or therapy is needed. CT enterography is valuable for assessing inflammatory bowel disease or other large bowel conditions but may not provide the same level of detail for small bowel lesions as capsule endoscopy. Abdominal ultrasound can offer some insights, particularly in assessing other abdominal organs, but it is