What is the workup for a 10-year-old with postprandial vomiting and melena for 2 weeks?

Workup of a 10-Year-Old with Postprandial Vomiting and Melena for 2 Weeks

Immediate Priority: Upper GI Bleeding Assessment

This child requires urgent esophagogastroduodenoscopy (EGD) as the primary diagnostic modality, as the combination of postprandial vomiting and melena strongly suggests upper gastrointestinal pathology, most likely peptic ulcer disease. 1

Initial Clinical Evaluation

Critical History Elements

• Vomiting characteristics: Determine if bilious (green), bloody (hematemesis), or projectile 2, 3
• Timing relationship: Postprandial pattern suggests gastric or duodenal pathology 1
• Stool appearance: Melena (tarry black stool) confirms upper GI bleeding source 1
• Underlying conditions: Screen for malignancy, chronic illness, NSAID use, or H. pylori risk factors 1
• Associated symptoms: Abdominal pain location, weight loss, fever, or systemic symptoms 4

Physical Examination Priorities

• Vital signs: Blood pressure and heart rate to assess hemodynamic stability 4
• Hydration status: Assess for dehydration from ongoing losses 5
• Abdominal examination: Palpate for tenderness, distention, masses, or peritoneal signs 2, 4
• Rectal examination: Confirm melena and rule out hematochezia 1

Laboratory Workup

Essential Initial Tests

• Complete blood count with differential: Hemoglobin level is critical—a drop ≥3 g/dL below normal limits significantly predicts upper GI source on endoscopy 1
• Comprehensive metabolic panel: Assess for electrolyte abnormalities and metabolic acidosis 5
• Coagulation studies: Rule out bleeding diathesis 1
• Type and screen: Prepare for potential transfusion if hemodynamically unstable 1

Additional Laboratory Considerations

• Liver function tests: Evaluate for portal hypertension and varices 1
• H. pylori testing: Serology or stool antigen if peptic ulcer suspected 1

Imaging and Endoscopic Evaluation

Primary Diagnostic Approach

• Esophagogastroduodenoscopy (EGD): This is the definitive first-line examination for melena in children, as the upper GI tract is the most common bleeding source 1
• Timing: Should be performed urgently, particularly if hemoglobin is significantly decreased or vomiting is present 1

Predictive Factors for Positive EGD Findings

The following factors significantly increase likelihood of identifying bleeding source on EGD: 1

• Presence of vomiting (as in this case)
• Hemoglobin ≥3 g/dL below normal limits
• Abnormal abdominal ultrasound findings

If EGD is Negative

• Small bowel capsule endoscopy: Consider if upper endoscopy reveals no source, as small intestine accounts for approximately 13% of melena cases in children 1
• Abdominal ultrasound: May identify masses, organomegaly, or vascular abnormalities 1

Expected Diagnoses by Frequency

Most Common Causes in Children with Melena

1. Duodenal ulcer (most common—40% of cases) 1
2. Gastric ulcer 1
3. Esophagitis 1
4. Esophageal varices (particularly if underlying liver disease) 1
5. Small bowel lesions (if upper GI source excluded) 1

Supportive Management During Workup

Hydration and Nutritional Support

• Oral rehydration: If tolerating oral intake, provide small frequent volumes of clear fluids 5, 6
• IV fluids: Initiate if hemodynamically unstable or unable to tolerate oral intake 5
• NPO status: Consider if endoscopy is imminent 1

Acid Suppression

• Proton pump inhibitor: Initiate empirically while awaiting endoscopy if peptic disease suspected 1

Antiemetic Consideration

• Ondansetron: May be used (0.15-0.2 mg/kg, max 4 mg) to control vomiting and facilitate oral intake, but only after adequate assessment 6, 7

Critical Pitfalls to Avoid

• Delaying endoscopy: The 2-week duration of symptoms with ongoing melena requires urgent evaluation, not conservative observation 1
• Assuming viral gastroenteritis: Melena is NOT consistent with simple gastroenteritis and demands investigation for structural pathology 1, 8
• Missing underlying conditions: Children with chronic illness, malignancy, or severe disorders have higher risk of significant GI pathology 1
• Inadequate hemoglobin monitoring: Serial CBCs are essential to detect ongoing bleeding 1
• Overlooking non-GI causes: While less likely with melena, consider systemic causes if GI workup is negative 3, 4

Disposition

• Hospitalization: Strongly consider admission for a child with 2 weeks of melena for expedited workup, monitoring, and endoscopy 1
• Surgical consultation: Have available if endoscopy reveals lesions requiring intervention or if perforation is suspected 2