How effective is oral rehydration therapy for gastroenteritis?

Gastroenteritis causes inflammation in the stomach or bowel and commonly brings diarrhoea, vomiting, nausea and cramps. These symptoms remove both water and salts. An oral rehydration solution uses glucose and electrolytes to help the bowel absorb fluid efficiently.

It eases the dehydration caused by the illness rather than directly stopping the virus or other trigger. Find more about [Gastroenteritis](/conditions/gastroenteritis/) and the treatment at [Oral Rehydration Therapy](/treatments/acute-and-urgent-care/oral-rehydration-therapy/).

Prepare the solution according to its instructions and offer small sips regularly. A spoon or syringe can help a child take tiny amounts. If vomiting happens, pause briefly, then restart slowly. Keep breastfeeding and offer normal food in small portions when tolerated.

Check for improving thirst, moisture in the mouth, normalising urine and better energy. Plain water can be added for general hydration, but it does not replace electrolytes lost with ongoing diarrhoea or vomiting.

Arrange urgent assessment for unusual drowsiness, confusion, fainting, no or very little urine, severe weakness, blood in stool, severe pain, repeated vomiting, or inability to drink. Fever with a very young child or a frail adult also warrants prompt advice.

Ask how to distinguish expected symptoms from dehydration, how much solution to offer, when food and usual medicines can resume, and whether another condition needs treatment.