Black Stools: Causes, Symptoms, and When to Seek Medical Attention

Dark, black stools that appear tarry (melena) often indicate bleeding in the upper gastrointestinal (GI) tract, which includes the esophagus, stomach, and first part of the small intestine. This can signal a serious medical condition requiring prompt evaluation.

Common Causes of Upper GI Bleeding

• Peptic ulcers (gastric or duodenal)
• Esophageal varices (enlarged veins in the esophagus, often due to liver disease)
• Gastritis or esophagitis
• Mallory-Weiss tear (tear in the esophageal lining from violent vomiting)
• Stomach cancer
• Use of certain medications (NSAIDs, anticoagulants)

Accompanying Symptoms That Warrant Immediate Care

• Abdominal pain or discomfort
• Nausea and vomiting (possibly with blood or "coffee-ground" material)
• Feeling faint, lightheaded, or dizzy
• Rapid heart rate (tachycardia)
• Shortness of breath
• Pale skin, cold sweats

If you notice black, tarry stools—especially with any of the above symptoms—seek medical attention immediately. A doctor can perform tests (such as endoscopy) to identify the bleeding source and initiate appropriate treatment.

Note: Iron supplements, bismuth subsalicylate (Pepto-Bismol), and certain foods (e.g., black licorice, blueberries) can also darken stools, but these typically do not produce a tarry texture or foul odor.