Diarrhea is a universal and recurring disease during childhood, with the global incidence estimated to be 2.7 episodes per child-year for children younger than 5 years. WHO defines diarrhea as the passage of unusually loose or watery stools, usually at least three times in a 24 hour period. Diarrhea has been associated with increased morbidity and mortality and is the third most common cause childhood mortality (responsible for 13% deaths in old) in India children less than 5 years each year. Diarrheal diseases can be classified according to their clinical pattern as acute watery diarrhea, persistent diarrhea, and acute bloody diarrhea (Figure 1). Some of the causes of diarrhea in infants and children are discussed in figure 2.