For an understanding of the treatment of diarrheal disturbances some consideration must be given to the underlying causes, the pathology and the symptomatology. The seriousness of diarrhea is attested by the fact that approximately 30 per cent or more of all deaths in the first year of life are attributable to gastro-enteric diseases and that even in the second year these still constitute the largest single cause of death. CAUSE OF DIARRHEA The symptom diarrhea is a common one and a manifestation of a great variety of diseases, some of which are not primarily gastro-enteric. Thus increased peristalsis and increased frequency of intestinal evacuation may occur in most febrile diseases, especially respiratory infections, in toxic or altered metabolic states such as uremia and acidosis, in emotional excitement and exposure to high or low external temperature, and in certain types of allergy. Diarrhea is helpfully eliminative when indigestible material is ingested