Diarrhea is a very common symptom in childhood. Most cases are acute, in relation with infectious agents. They resolve in few days, the main complication being acute dehydration. At the opposite, chronic diarrhea may be complicated by denutrition and failure to thrive. In most cases, the symptom is related to a chronic nonspecific diarrhea of childhood, without any nutritional consequence and the family will be reassured. Sometimes, clinical data suggest an organic etiology. In this case, additional investigations will be performed, taking into account the semiology of the diarrhea and the relative frequency of the different etiologies.