From the Guidelines
Based on your history of a single episode of melena 4 years ago with normal colonoscopy, endoscopy, and abdominal CT scan with contrast, and no recurrence since then, there is generally no need to specifically check the small intestine at this time. Since you had a comprehensive workup that was negative and have remained symptom-free for 4 years, the bleeding episode was likely self-limited and has resolved. The most common causes of melena are typically found in the upper GI tract (which was examined by endoscopy) or the colon (examined by colonoscopy), and the CT scan would have likely detected any significant masses or abnormalities in the small intestine. Small intestine evaluation through capsule endoscopy or enteroscopy is typically reserved for cases with ongoing or recurrent bleeding without an identified source, unexplained iron deficiency anemia, or when there are specific symptoms pointing to small bowel disease, as suggested by the American Gastroenterological Association (aga) institute medical position statement on obscure gastrointestinal bleeding 1. If you develop new symptoms such as recurrent melena, persistent abdominal pain, unexplained weight loss, or anemia, you should consult your doctor promptly for reassessment and possible additional testing of the small intestine at that time, considering the latest recommendations on the role of imaging for GI bleeding 1. Key points to consider include:
- The role of capsule endoscopy in identifying intestinal bleeding lesions, especially in cases with negative upper and lower endoscopy results 1.
- The use of CT enterography (CTE) as a first-line imaging test for suspected small bowel bleeding in hemodynamically stable patients, especially if there is a suspicion of small bowel neoplasm or if video capsule retention is a concern 1.
- The importance of clinical judgment in deciding when to pursue further evaluation of the small intestine, taking into account the patient's overall clinical presentation and risk factors.
From the Research
Evaluation of Melena
- Melena, or tarry black stool, can be caused by bleeding from various sources in the gastrointestinal tract, including the upper gastrointestinal tract, small intestine, and lower gastrointestinal tract 2, 3, 4, 5, 6.
- In patients with melena and normal colonoscopy, endoscopy, and abdominal CT scan with contrast, the small intestine may be a potential source of bleeding 2, 3.
Diagnostic Yield of Small Intestine Evaluation
- The diagnostic yield of small intestine evaluation, such as capsule endoscopy, can be significant in patients with melena and negative upper and lower endoscopy 3.
- Earlier use of capsule endoscopy in patients with melena or severe iron deficiency anemia can reduce the need for colonoscopy and shorten hospital stay 3.
- Small bowel capsule endoscopy may be useful in identifying the bleeding source in patients without upper gastrointestinal lesions 2.
Risk of Missing a Potential Bleeding Source
- If only colonoscopy or only esophagogastroduodenoscopy is performed, a potential bleeding source may be missed in a significant proportion of patients 6.
- Approximately 25% of patients with a potential bleeding source in the upper gastrointestinal tract could have been missed if only colonoscopy had been performed, and nearly the same proportion of patients could have been missed if only esophagogastroduodenoscopy had been performed 6.
Recommendations for Evaluation
- Patients with melena and normal colonoscopy, endoscopy, and abdominal CT scan with contrast may benefit from further evaluation of the small intestine, such as capsule endoscopy 3.
- The decision to evaluate the small intestine should be based on individual patient factors, such as the presence of ongoing bleeding or iron deficiency anemia 3, 4, 5.