Diarrhea: Differential Diagnosis by Symptom Pattern

• •Pain location and relation to meals
• •Stool pattern (watery, bloody, greasy) and vomiting profile
• •Associated systemic signs such as fever or jaundice

• •Prioritize red flags and severe progression first
• •Use focused history + exam to define the leading organ system

• •Fever pattern and inflammatory signs
• •Exposure history, travel risk, and host immunity
• •Organ-localized signs vs systemic sepsis pattern

• •Character of pain and exertional trigger
• •Hemodynamic instability, pulse pattern, and blood pressure
• •ECG and cardiac biomarkers trend

• •Morphology and distribution of skin findings
• •Trigger/exposure timing and recurrence pattern
• •Systemic involvement (airway, hemodynamics, fever)

Immediate testing when red flags are present

• •Vital signs and focused triage examination
• •Pulse oximetry and ECG
• •Basic blood panel (CBC, CRP, electrolytes, glucose)
• •Immediate imaging based on dominant red flags

Group-directed workup

• •CBC / CRP
• •Liver panel and lipase
• •Stool tests
• •Abdominal ultrasound
• •CBC with differential
• •CRP / ESR
• •Targeted cultures or PCR
• •Lactate if sepsis concern