This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
Most common cause of diarrhea in children of developing countries is: 
Select and explain. 
A. EHEC, B. ETEC, C. EAEC, D. EIEC
B: ETEC
Answer: B: ETEC 
Explanation: ETEC Most frequent bacterial cause of diarrhea in children of developing countries. Most common cause of traveler's diarrhea. EPEC Cause infantile diarrhea (outbreaks) Rarely sporadic diarrhea in adults.