The observation that the intestinal Na(+)-
glucose cotransporter remains intact in most diarrheal illnesses led to development of the life-saving, low-cost technology of
oral rehydration salt (
ORS) solutions. The primary therapeutic role of
ORS solutions is in prevention and treatment of
dehydration during management of acute
gastroenteritis. Successful
oral rehydration therapy involves early use of
ORS with maintenance or timely resumption of regular feeding. Since the inception of the
oral rehydration approach more than three decades ago, the widespread use of
ORS solutions has revolutionized the management and outcomes of acute
gastroenteritis in children and adults. The efficacy of the World Health Organization
ORS solution and of commercial
ORS formulations has been enhanced by reducing osmolarity. Newer formulations of
ORS are under active investigation, with promise of added benefits, including promotion of intestinal healing. This article reviews fluid and
electrolyte transport in the gastrointestinal tract, the pathophysiologic mechanisms of acute
diarrhea, and the basis and formulation of current and newer
ORS solutions. Guidelines for efficacious use of
ORS in the management of acute
gastroenteritis and short gut syndrome are also provided.