Black Stool (Melena): Upper GI Bleeding Warning Sign

Black, tarry, foul-smelling stools (melena) indicate digested blood from the upper GI tract (esophagus, stomach, duodenum). Common causes:

• Peptic ulcer disease (H. pylori, NSAIDs).
• Esophagitis, Mallory-Weiss tear, varices.
• Gastritis, vascular malformations.

Differential

• Iron supplements, bismuth (Pepto-Bismol), black licorice, blueberries – cause dark but non-tarry stool.

Urgency

Melena is a medical emergency. Seek immediate evaluation: hemodynamics, labs (CBC, coag, type & screen), urgent endoscopy within 24h. Do not wait.