Management of Blackish Stool (Melena)
Patients presenting with melena require immediate risk stratification, resuscitation if hemodynamically unstable, and urgent upper endoscopy within 24 hours, as melena indicates upper gastrointestinal bleeding with mortality rates of 11% in admitted patients and up to 33% in hospitalized patients who develop bleeding. 1
Initial Assessment and Resuscitation
Hemodynamic Evaluation
Immediately assess for signs of significant bleeding:
- Vital signs: Pulse >100 bpm, systolic BP <100 mmHg indicate shock 1
- Hemoglobin: Drop >20 g/L over 24 hours suggests ongoing bleeding 1
- Clinical presentation: Melena alone typically indicates less severe bleeding than melena with hematemesis 1
Risk Stratification
Use validated prognostic scales to categorize patients 2:
- Blatchford score (pre-endoscopy): Includes hemoglobin, blood urea, pulse, BP, syncope, melena, hepatic disease, cardiac failure—accurately identifies low-risk patients who may not require intervention
- Rockall score (complete): Best discriminates mortality risk; incorporates endoscopic findings
Critical point: Approximately 10-15% of patients presenting with apparent lower GI bleeding (including melena) actually have an upper GI source 3
Immediate Management
Resuscitation Protocol
- IV access: Two large-bore lines
- Blood transfusion: Administer if hemoglobin indicates significant blood loss 2
- Proton pump inhibitors: Start IV PPI immediately, especially if peptic ulcer suspected 4, 5
- Specialist consultation: Transfer care to gastroenterology (medical or surgical) 1
Staffing Requirements
Patients must be under the care of a gastroenterologist (medical or surgical) with 24-hour observation capability and experienced nursing staff 1. Mortality is lower in specialist units due to protocol adherence 1.
Diagnostic Approach
Upper Endoscopy (First-Line)
Perform esophagogastroduodenoscopy within 24 hours 6, 5, 7:
- Provides both diagnosis and therapeutic intervention
- Identifies the bleeding source in ~80% of cases 1
- Most common causes:
- Peptic ulcer: 35-50%
- Gastroduodenal erosions: 8-15%
- Esophagitis: 5-15%
- Varices: 5-10%
- Mallory-Weiss tear: 15% 1
High-Risk Endoscopic Findings
Predict rebleeding and require immediate intervention 1, 2:
- Active arterial bleeding
- Non-bleeding visible vessel
- Adherent clot
- Ulcer >2 cm
- Posterior duodenal or lesser gastric curvature location
Therapeutic Interventions
Endoscopic Therapy
For ulcers with major stigmata 4, 5:
- Injection therapy: Dilute adrenaline (epinephrine)
- Thermal methods: Heater probe, multipolar electrocoagulation, argon plasma coagulation
- Mechanical: Endoclips
- Combination therapy preferred over injection alone 7
Medical Management
- IV omeprazole: Reduces rebleeding risk post-endoscopic therapy 4
- Continue high-dose PPI after endoscopic hemostasis
Management of Rebleeding
Rebleeding defined as 1:
- Fresh hematemesis/melena with shock (pulse >100, BP <100)
- CVP fall >5 mmHg
- Hemoglobin drop >20 g/L over 24 hours
Always confirm rebleeding by repeat endoscopy 1. Options include:
- Repeat endoscopic therapy
- Interventional radiology (transcatheter embolization) 8
- Surgical intervention if endoscopic/radiologic approaches fail
Special Considerations
Variceal Bleeding
If varices identified:
- Endoscopic band ligation (preferred) or sclerotherapy 4
- Vasoactive drugs (octreotide, terlipressin) 5
- Manage underlying liver disease
Hemodynamically Unstable Patients
For patients requiring >5 units blood in 24 hours 8:
- CTA abdomen/pelvis with IV contrast OR
- Transcatheter arteriography/embolization as equivalent first-line options
Common Pitfalls to Avoid
Don't assume lower GI source: 10-15% of melena cases have upper GI bleeding despite appearing to be lower GI 3
Don't delay endoscopy: Mortality is lower with early intervention in specialist units 1
Dietary mimics exist: Black stool from bismuth, iron supplements, or certain foods (chocolate cookies, licorice) can mimic melena 9—but in true melena, stool is tarry and sticky, not just dark
Don't use injection therapy alone: Combination with thermal or mechanical methods improves hemostasis 7
Elderly patients with comorbidities: Have highest mortality risk; require intensive monitoring 1, 2