Following rehydration, stool output will be measured for a 4-hour period in the maintenance phase, to be called “Observation Period”, and those with a stool output of ³ 20 ml/kg during this period and those who also have V. cholerae demonstrated in their stool dark-field examination will be considered eligible for enrollment into the study if they provide voluntary informed consent. This observation period will help establish that patients enrolled in the study have moderate to severe disease, so that the potential impact of therapy can be evaluated (as any therapy is likely to appear effective in mild disease).