For an adult with black stools (melena) and no systemic symptoms, what is the most appropriate initial diagnostic test?

• A. Colonoscopy
• B. Upper Endoscopy
• C. Abdominal CT
• D. Stool for Occult Blood

Answer: (D)

The main idea here is to start with a noninvasive confirmation of bleeding before moving to invasive localization and treatment. When an adult presents with melena and is hemodynamically stable, the quickest way to verify that there is ongoing GI bleeding is to obtain a stool test for occult blood. This simple, inexpensive test documents the presence of blood in the stool and helps establish that bleeding is occurring, which then guides the urgency and sequencing of further workup. It serves as a practical initial step that won’t delay care, while you plan definitive evaluation.

Upper endoscopy is the definitive diagnostic and therapeutic tool for suspected upper GI bleeding, but it is invasive and should follow initial confirmation of bleeding. Abdominal CT isn’t the first choice for suspected GI bleeding and endoscopy- or risk-directed planning, and colonoscopy focuses on the lower GI tract and is less useful as an immediate initial test when melena points toward an upper GI source.