REHYDRATION AND maintenance of adequate fluid and electrolyte balance is the key to the management of the child with acute diarrheal disease. Oral rehydration treatment has been shown to be simple, practical, inexpensive, highly effective and safe for developing as well as for developed countries. A better understanding of the physiological mechanisms implicated in diarrheal illness as well as extensive clinical testing of oral rehydration solutions have lead to the improvement of the composition of electrolyte, carbohydrate and base constituents. The widespread use of oral rehydration therapy may result in a decreased need for hospitalization and less discomfort and complications which are associated with intravenous rehydration therapy.