Dioralyte is used for replacement of lost fluids and electrolytes associated with acute diarrhoea. How does it work? Dioralyte sachets contain rehydration salts consisting of sugars and salts (glucose, sodium chloride, potassium chloride and disodium hydrogen citrate). Dioralyte is used to replace body fluids lost as a result of acute diarrhoea. Diarrhoea makes you lose more fluids and electrolytes (salts such as sodium and potassium) than you usually would and can make you dehydrated.Dioralyte Sachets of rehydration salts are used to replace body fluids lost as a result of diarrhoea. This is particularly important in frail and elderly people and children with diarrhoea. The contents of the sachets are dissolved in water to provide the fluid. The sugar (glucose) that is in the sachets helps the water and electrolytes to be absorbed from the intestines.