Melena
Melena refers to black, tarry, sticky stools with a distinctive foul odor, indicating bleeding in the upper gastrointestinal tract. The dark color results from blood being digested as it passes through the intestines. This serious symptom always requires immediate medical evaluation, as it can indicate life-threatening bleeding that needs urgent treatment.
🚨 MEDICAL EMERGENCY - Call 911 Immediately For:
- Black, tarry stools (melena)
- Dizziness, weakness, or fainting
- Rapid heart rate or palpitations
- Pale skin or cold sweats
- Shortness of breath
- Confusion or altered mental state
- Severe abdominal pain
- Vomiting blood
- Low blood pressure
- Chest pain
DO NOT WAIT - Melena indicates potentially life-threatening internal bleeding requiring immediate emergency evaluation and treatment.
Understanding Melena
Melena occurs when blood from the upper gastrointestinal tract (esophagus, stomach, or upper small intestine) is digested by stomach acid and intestinal bacteria, turning it black and tarry. At least 50-100ml of blood is typically required to produce melena. The characteristic appearance and odor make it distinguishable from other causes of dark stools.
The black color results from the oxidation of iron in hemoglobin as blood passes through the digestive system. Unlike fresh red blood in stool (hematochezia), which indicates lower GI bleeding, melena's dark appearance confirms the blood has been in the GI tract long enough to be chemically altered, pointing to an upper source of bleeding.
Common Causes
Peptic Ulcer Disease
- Gastric ulcers
- Duodenal ulcers
- H. pylori infection
- NSAID-induced ulcers
- Stress ulcers
- Bleeding ulcers
Esophageal Causes
- Esophageal varices
- Mallory-Weiss tears
- Esophagitis
- Esophageal cancer
- Boerhaave syndrome
- Severe GERD
Gastric Causes
- Gastritis
- Stomach cancer
- Gastric varices
- Dieulafoy lesion
- GAVE (watermelon stomach)
- Portal hypertensive gastropathy
Other Causes
- Bleeding disorders
- Anticoagulant medications
- Upper GI tumors
- Aortoenteric fistula
- Hemobilia
- Swallowed blood (nosebleed)
Distinguishing True Melena
Characteristics of Melena
- Black, tarry consistency
- Sticky texture
- Distinctive foul odor
- Difficult to flush
- Shiny appearance
- Consistency like tar or asphalt
Not Melena (False Melena)
- Iron supplements (hard, black pellets)
- Bismuth medications (Pepto-Bismol)
- Black foods (licorice, blueberries)
- Charcoal supplements
- Dark green vegetables (may appear black)
Associated Warning Signs
Melena often occurs with symptoms of blood loss and the underlying condition:
- Hematemesis: Vomiting blood
- Lightheadedness: From blood loss
- Fatigue: Anemia symptoms
- Pallor: Pale skin
- Tachycardia: Rapid heart rate
- Hypotension: Low blood pressure
- Abdominal pain: From underlying cause
- Syncope: Fainting episodes
Risk Factors
- NSAID use: Aspirin, ibuprofen
- Alcohol abuse: Liver disease, varices
- H. pylori infection: Ulcer risk
- Anticoagulation: Blood thinners
- Previous GI bleeding: Recurrence risk
- Liver cirrhosis: Portal hypertension
- Age over 60: Higher risk
- Smoking: Ulcer risk
Emergency Evaluation
Immediate Assessment
- Vital signs monitoring
- IV access establishment
- Blood type and crossmatch
- Complete blood count
- Coagulation studies
- Metabolic panel
Diagnostic Procedures
- Upper endoscopy: Gold standard
- Nasogastric lavage: Assess active bleeding
- CT angiography: If endoscopy negative
- Capsule endoscopy: Small bowel evaluation
- Tagged RBC scan: Intermittent bleeding
Emergency Treatment
Immediate Interventions
- Fluid resuscitation
- Blood transfusions
- Proton pump inhibitors IV
- Octreotide (for varices)
- Correction of coagulopathy
- Antibiotics (cirrhosis patients)
Definitive Treatment
- Endoscopic therapy
- Variceal banding
- Sclerotherapy
- Thermal coagulation
- Hemoclip application
- Angiographic embolization
- Surgery if needed
What to Do If You Have Melena
- Call 911 immediately: Don't wait or drive yourself
- Stop all NSAIDs: Including aspirin
- Nothing by mouth: Prepare for procedures
- Lie down: Prevent fainting
- List medications: Especially blood thinners
- Note symptoms: When started, amount
- Have someone stay: Monitor condition
- Bring stool sample: If safely possible
Prevention
- Limit NSAIDs: Use alternatives when possible
- Treat H. pylori: If present
- Manage GERD: Reduce acid damage
- Alcohol moderation: Prevent liver disease
- Medication review: With doctor
- Regular screening: High-risk patients
- Stress management: Reduce ulcer risk
- Follow-up care: After any GI bleeding