Diarrheal disease is one of the leading causes of worldwide childhood morbidity and mortality, resulting in 1.4 to 2.5 million deaths annually [1-3]. Loss of intestinal fluid caused by gastroenteritis may lead to severe hypovolemia, shock, and death, particularly in children younger than five years of age.
Although the total number of deaths globally from diarrheal diseases remains high, the overall mortality rate has steadily declined over the last few decades . This decline, especially in developing countries, is largely due to the use of early and appropriate oral rehydration therapy (ORT), as well as improved nutrition and water sanitation measures .
In the United States, diarrhea caused by gastroenteritis remains the major cause of hospitalizations (>200,000/year) and outpatient visits (>1.5 million/year); this results in 300 deaths every year . The annual direct medical costs are estimated to be more than 1 billion US dollars per year.
The early use of ORT at home in children with diarrhea decreases the number of outpatient visits and hospitalizations, and overall medical costs . Despite the success of ORT in developing countries, and established guidelines supporting its use in children with gastroenteritis by the American Academy of Pediatrics (AAP) and the Centers for Disease Control (CDC), the full benefit of ORT in the United States and other developed countries has not been realized on account of underutilization [5-9].
The scientific basis and clinical application of ORT in patients with diarrhea, the composition of oral rehydration solutions (ORS), and the limitations and barriers to this therapy are discussed in this topic review. The assessment and treatment of hypovolemia in children is discussed separately. (See "Clinical assessment and diagnosis of hypovolemia (dehydration) in children" and "Treatment of hypovolemia (dehydration) in children".)