In a 12-month community study in Ecuadorian preschool children, we compared a packaged rice-based oral rehydration solution (R-ORS) that contained 160 g of rice flour and 12 g of sucrose per liter as well as electrolytes and alpha-amylase, and required cooking before consumption, to the standard glucose-electrolyte oral rehydration solution (G-ORS) for the treatment of acute noncholera diarrhea. The reconstituted R-ORS had energy and protein contents of 620 kcal/L and 12g/L, respectively, and an osmolarity of 230 mosm/L. In all, 156 cases were treated with the R-ORS and 144 with the standard G-ORS. Cases treated with R-ORS had a significantly shorter duration of diarrhea (p < 0.0001; median; 34 h versus 48 h), a lower number of stools (p < 0.001; median; four versus seven), and a greater weight gain after 4 days of treatment (p < 0.05; mean; 1.6% versus-0.2%) than those treated with G-ORS. ORS and total liquid intakes tended to be higher with the R-ORS. The two ORS were equivalent for the correction of mild dehydration and the maintenance of normal hydration status.