From the Guidelines
The next step in diagnosing a 50-year-old man with melena after normal upper GI endoscopy and colonoscopy results should be a video capsule endoscopy (VCE) to evaluate the small bowel. This recommendation is based on the strongest and most recent evidence from the clinical practice guidelines for the use of video capsule endoscopy 1. The patient should be prepared with a clear liquid diet the day before and fasting for at least 12 hours prior to swallowing the capsule. Some key points to consider:
- The small bowel is a common source of occult bleeding, particularly in middle-aged patients where small bowel tumors, Crohn's disease, or vascular lesions may be present.
- Video capsule endoscopy allows visualization of the small intestine, which is not accessible by standard endoscopy or colonoscopy.
- If the video capsule endoscopy is negative, additional testing may include CT enterography or MR enterography to look for small bowel lesions that might be missed by capsule endoscopy.
- Alternatively, if there is high suspicion for a small bowel source and the patient continues to have melena, a push enteroscopy or balloon-assisted enteroscopy might be considered for direct visualization and potential intervention. The American Gastroenterological Association (AGA) institute medical position statement on obscure gastrointestinal bleeding also supports the use of capsule endoscopy in patients with obscure GI bleeding 1. However, the most recent and highest quality study is the 2017 clinical practice guidelines for the use of video capsule endoscopy 1, which provides a strong recommendation for the use of CE in patients with documented overt gastrointestinal (GI) bleeding and negative findings on high-quality EGD and colonoscopy. Therefore, video capsule endoscopy is the recommended next step in diagnosing this patient.
From the Research
Next Steps in Diagnosing Melena
Given the normal results from upper GI endoscopy and colonoscopy, the next step in diagnosing a 50-year-old man with melena would involve investigating the small bowel, as this is a common site for bleeding that may not be detected by standard endoscopy or colonoscopy.
- Capsule Endoscopy: This is a diagnostic tool that allows for the visualization of the small bowel mucosa, which is often not accessible through conventional endoscopy or colonoscopy 2, 3. It is particularly useful for detecting sources of obscure gastrointestinal bleeding, such as arteriovenous malformations, small bowel tumors, and ulcers that may have been missed by other diagnostic methods.
- Indications and Findings: Studies have shown that capsule endoscopy can identify lesions within the reach of conventional endoscopy and colonoscopy that were initially missed, including gastric and colonic lesions 4. It has a high diagnostic yield for patients with obscure GI bleeding, with findings such as bleeding sites, angiodysplasia, ulcers, and tumors 5.
- Procedure and Limitations: While capsule endoscopy is well-tolerated and easy to perform, it has limitations, including the inability to treat lesions during the procedure and potential issues with bowel preparation, transit time, and camera orientation, which can lead to missed lesions 2.
- Comparison with Other Methods: Capsule endoscopy has been compared with push-enteroscopy and other imaging techniques, showing its utility in visualizing the small bowel and detecting bleeding sites or other pathology that might not be accessible or visible through other means 3, 5.
Decision Making
Considering the patient's presentation with melena and normal upper GI endoscopy and colonoscopy results, the most appropriate next step would be to perform a capsule endoscopy to investigate the small bowel for potential sources of bleeding. This approach is supported by the evidence showing the effectiveness of capsule endoscopy in diagnosing obscure GI bleeding and its ability to detect lesions that may have been missed by other diagnostic methods 2, 3, 4, 5.