Severe diarrhoea, vomitting, watery stools are the chief symptoms of cholera. All these lead to dehydration. Actually, cholera toxin secreted by Vibrio cholerae causes, through a series of metabolic reactions, the continuous activation of adenylate cyclase of intestinal epithelial cells. The resultant high concentration of c-AMP triggers continuous secretion of $Cl ^{-}, HCO _{3}^{-}$and water into the lumen of the intestine. Administration of saline not only supports the sodium-potassium pump through which water in cell is restored, but glucose is also symported along with sodium.