In contrast to adults, infants and young children with dehydration often have a build up of a certain type of acid in their blood which can perpetuate the nausea, vomiting, and general malaise associated with gastroenteritis. The investigators feel that giving these children IV fluids with lots of sugar (in addition to the salt) reduces the acid more rapidly than giving just salt water alone. In a prior study, the investigators have shown that children who receive lower amounts of sugar in the IV fluids return to the Emergency Department more often for a second visit. Based on this study, the investigators believe that children who receive the sugar-salt solution will do better than children who receive just normal saline.