Poor sanitary conditions in disaster-stricken areas result in higher risk for diarrheal illness in vulnerable populations, especially children. This disease negatively impacts the nutritional status of affected children and causes significant morbidity and mortality. Early diagnosis and treatment are thus essential to reduce the impact of diarrheal diseases on people affected by disasters. Early identification of cases allows the implementation of measures needed to prevent or lessen outbreaks that can occur in displaced populations in this context. The use of primary care management tools, such as the Integrated Management of Childhood Illness (IMCI) strategy is highly important.This module will first discuss diarrheal diseases and their management, and dehydration and its treatments.