Scientific rationale for oral rehydration therapy.

A scientific rationale for the use of oral rehydration therapy (ORT) in treating severe diarrhea is presented. Because diarrhea impairs the absorptive and secretory functions of the gastrointestinal tract, volume and solute deficits must be corrected through ORT. The composition of the ideal ORT solution--one that maximizes absorption of water, electrolytes, and nutrients--is discussed in relation to the digestive-absorptive mechanisms of the gut.