The present invention provides therapeutic compositions and methods for treating gastrointestinal diseases and conditions such as diarrhea, for providing rehydration, for correcting electrolyte and fluid imbalances, and/or for improving small intestine function. In one embodiment, the present invention provides a composition formulated for enteral administration, wherein the composition does not contain glucose. In a preferred embodiment, the composition is formulated for administration as an oral rehydration drink.