Learning Objectives: After reading this chapter and answering the discussion questions that follow, you should be able to Define the different types of childhood diarrhea and distinguish their clinical manifestations. Describe the magnitude and unequal distribution of childhood diarrhea by age group and by different world regions. Analyze the relative contributions of different diarrhea pathogens, as well as environmental and socio-behavioral risk factors to the causation of childhood diarrhea. Appraise and prioritize the evidence base of various treatment and prevention options. © Springer Science+Business Media, LLC 2009.