The standard packaged glucose-based oral rehydration solution (ORS) provides optimal rehydration of acute diarrhea from any cause, but it does not reduce the volume, frequency, or duration of diarrhea. A new ORS formulation has been developed in which glucose is replaced by 50 to 60 gm of cereal flours, such as rice, wheat, maize, sorghum, or millet, or equivalent amounts of noncereal staples, such as boiled potato or plantain. In a clinical trial in children suffering from acute diarrhea, the staple-based or polymer-based ORS achieved a 40% to 60% reduction in the stool volume compared with the standard ORS. A three-cell longitudinal study in rural Bangladesh involving 2,000 children aged 1 to 4 years demonstrated the superior efficacy of rice ORS compared with glucose ORS or no ORS. The cumulative recovery rate on day 3 was 66%, 24%, and 11% in the rice ORS, glucose ORS, and comparison groups, respectively. The study suggests that staple-based or food-based ORS is the optimal treatment of diarrhea.