What causes gastroenteritis?

An infection inflames the lining of the stomach and intestines. This can lead to diarrhoea, vomiting, stomach cramps, nausea and sometimes fever. Germs may spread through close contact, shared surfaces, unsafe food or untreated water. Symptoms can begin after swallowing the organism and may affect several people in the same household.

Take frequent small sips of water or an oral rehydration drink, especially after vomiting or loose stools. Rest, eat simple foods when appetite returns, and wash hands with soap and water. Avoid preparing food for others while unwell and clean contaminated bathroom surfaces. Do not start antibiotics unless a clinician advises them.

Seek urgent medical help for severe dehydration, fainting, confusion, blood in vomit or stool, severe abdominal pain, or inability to keep fluids down. Contact a clinician if symptoms are worsening, prolonged, or affecting a young child, older adult, pregnant person, or someone with a long-term illness.

Ask which fluids are suitable, whether testing is needed, and how to manage medicines during vomiting or diarrhoea.