Studies of "improved" oral rehydration solutions, in which glucose polymers (starch) derived from rice or other cereals were added to improve cotransport of sodium and to promote sodium and water absorption, have been reported. These solutions were administered to decrease diarrhea volume and duration, reduce vomiting, and replace volume loss in stools. In clinical trials of children and adults with high-output diarrhea, such as in cases of cholera, the use of cereal-based oral rehydration solutions (ORS) compared with glucose-based ORS produced significant (20% to 53%) reductions in stool volumes. In one study the duration of diarrhea was shortened by 30%. In noncholera diarrhea in children, cereal-based ORS was as effective as glucose-based ORS. Although the amino acid transport systems were intact in patients with cholera, the addition of glycine to glucose-based or rice-based ORS did not reduce stool volume or duration of diarrhea. The exception was alanine, which reduced stool output and ORS requirements. More research is needed to determine the optimal mix of starch, amino acids, oligopeptides, and proteins that would utilize the absorptive active transport systems maximally to reduce fluid losses and duration of diarrhea.