Patients who meet the initial entry criteria will be admitted into the study ward of the ICDDR,B, weighed (Dehydration Weight), assessed for hydration status and rehydrated using an intravenous polyelectrolyte solution (“Dhaka Solution” containing 133 mmol/l of sodium, 13 mmol/l of potassium, 98 mmol/l of chloride and 48 mmol/l of bicarbonate) over a 3-hour period in accordance with the WHO guidelines [53], and re-weighed (Rehydration Weight). Rice-based oral rehydration salts (ORS) solution (sodium 90 mmol/l, potassium 20 mmol/l, chloride 80 mmol/l, bicarbonate 30 mmol/l, and rice powder 50 gram per litre) will be used as the primary maintenance fluid once initial rehydration is accomplished, however, intravenous polyelectrolyte solution will be used as the maintenance fluid for patients with excessive vomiting (usually > 4 episodes per hour) or with rapid stool losses (usually >10 ml/kg.hour), or those who are unable to drink enough ORS solution for maintenance of their hydration. Patients will be allowed to drink plain water ad libitum after the initial rehydration. All fluid intake and output during rehydration (and throughout the study) will be recorded. A stool specimen will be collected from the patients for dark-field microscopic examination to document the presence of V. cholerae.