Melena

Definition

Melena is the passage of black, tarry, foul-smelling stool resulting from digested blood, usually from upper gastrointestinal bleeding (esophagus, stomach, duodenum).

Causes

• Peptic ulcer disease
• Esophageal varices
• Gastritis, esophagitis
• Mallory-Weiss tear
• Gastric cancer
• NSAID or anticoagulant-related bleeding

Differentiation From Other Dark Stools

Iron supplements and bismuth (Pepto-Bismol) darken stools but are not tarry or foul-smelling. Positive guaiac test confirms blood.

Nursing Interventions

Assess for other signs of GI bleeding (hematemesis, hypotension, tachycardia). Establish IV access, type and crossmatch, CBC, BUN (often elevated due to blood protein digestion). Administer IV fluids and blood products as ordered. Prepare for urgent EGD. NPO status.

NCLEX Relevance

Black tarry stool = upper GI bleed.