What should you know about different types of stomach flu?

Stomach flu is not influenza. It describes irritation and inflammation in the stomach and intestines. Viral gastroenteritis can spread easily between people; food- or water-borne bacteria and parasites may cause a similar pattern. Symptoms can include diarrhoea, nausea, vomiting, abdominal pain, fever and loss of appetite. Rotavirus infection is one viral cause, particularly relevant to young children.

The cause cannot always be identified from symptoms alone. The pattern, recent meals, travel, sick contacts, medicines and other health conditions help a clinician decide whether testing or treatment is needed.

Take frequent small sips of water or an oral rehydration drink, especially after vomiting or diarrhoea. Continue eating light foods when tolerated, and rest. Wash hands with soap and water, clean contaminated surfaces, and avoid preparing food for other people while unwell. Children, older adults and people with other illnesses can become dehydrated more quickly.

Do not start antibiotics just because diarrhoea is present; they help only selected bacterial infections. A clinician can advise whether a medicine is suitable for your symptoms and health history.

Arrange medical advice if you cannot keep fluids down, diarrhoea is persistent, or symptoms are worsening. Seek urgent help for confusion, fainting, very little urine, severe abdominal pain, blood in stool or vomit, or signs of significant dehydration. Fever with marked weakness or illness after travel or a risky food exposure also deserves prompt assessment.

Ask what cause is most plausible, how to replace fluids, whether testing is useful, which foods and medicines are suitable, and when you can safely return to work, school or childcare.