Diarrhoea and vomiting caused by gastroenteritis in under 5s: diagnosis and management

Preventing and treating dehydration

If your child has gastroenteritis but is not dehydrated, keep feeding them as normal (for example, breast milk) and offer regular drinks. Fruit juice and fizzy drinks should be discouraged because they can make the diarrhoea worse. Your healthcare professional may recommend that you give your child a special fluid called oral rehydration salt solution (sometimes called ORS solution) to drink to prevent your child from becoming dehydrated. Oral rehydration salt solution is made up from a powder and is only available from pharmacies. It is made up of water, sugar and salts in specific amounts. It helps to replace the water and salts lost from the body because of diarrhoea and vomiting – this is called rehydration.

If your child is dehydrated this can usually be treated by giving them oral rehydration salt solution frequently in small amounts over a period of about 4 hours. Your healthcare professional should explain how to use the solution. During this time, if your child is breastfeeding, continue with this; otherwise, you should not give your child any other drinks unless your healthcare professional specifically tells you that it is OK to do so. Your child should not eat solid food until they are rehydrated.

Many children vomit a little when they start to drink the oral rehydration salt solution. However, if your child keeps vomiting or will not drink the solution, you should contact a healthcare professional. If your child is being treated in hospital and this happens, they may need to have the solution through a tube that passes through their nose into the stomach.