In most cases of diarrhoea, the danger is not the infection itself but the fluid and salts lost with it. Replacing them early is what keeps people, and especially young children, out of hospital.
Using oral rehydration salts (ORS)
Mix one sachet with the exact volume of clean, safe water stated on the sachet — usually one litre. Do not add sugar, and do not use less water to make it "stronger". Give small sips frequently rather than a large glass at once, and continue after every loose stool.
Zinc for children
The World Health Organization recommends zinc alongside ORS for children with diarrhoea; ask the pharmacist for the appropriate preparation and duration for the child's age.
Keep eating
Continue breastfeeding infants, and offer normal food to older children and adults as soon as they can manage it.
Go to a clinic if
There is blood in the stool, repeated vomiting, a high fever, signs of dehydration (sunken eyes, very little urine, drowsiness, a dry mouth, or in a baby a sunken fontanelle), or diarrhoea lasting more than a few days.