What should you know about any stomach flu going around?

Vomiting, watery diarrhoea, nausea, abdominal cramps, fever and reduced appetite can occur with several viral or bacterial illnesses. Influenza mainly affects the respiratory system, so the everyday name “stomach flu” can be confusing.

Several people becoming unwell after sharing a meal may suggest a food-related source, while illness passing through a household can fit a contagious infection. Neither pattern proves the cause. Recent travel, antibiotic use, affected contacts, blood in the stool and the ability to keep fluids down help determine whether testing or treatment is needed.

The main immediate concern is fluid loss. Infants, older adults, pregnant people and anyone with kidney disease, diabetes or reduced immunity may become unwell more quickly and deserve earlier clinical advice.

Take frequent small sips of oral rehydration solution, especially when nausea makes a full drink difficult. Continue breast milk or usual milk feeds for a baby unless a clinician advises differently. Eat light, familiar foods when appetite returns; forcing food is less useful than maintaining fluids.

Wash hands thoroughly with soap and water after using the toilet or helping an unwell person, and before handling food. Clean contaminated bathroom surfaces, launder soiled items separately, do not share towels or utensils, and avoid preparing meals for others while vomiting or diarrhoea continues. Ask a pharmacist or clinician before giving anti-diarrhoeal medicine to a child.

Seek urgent help for marked drowsiness, confusion, fainting, severe or localised abdominal pain, a rigid or swollen abdomen, vomit containing blood or green fluid, black or bloody stool, or difficulty breathing. A baby who is unusually sleepy, has a sunken soft spot or is feeding poorly also needs prompt assessment.

Contact a clinician when fluids repeatedly come back up, urine becomes very scant or dark, the mouth stays dry, dizziness occurs on standing, fever is concerning, or symptoms are worsening rather than settling. Mention recent travel, antibiotics, pregnancy and chronic medical conditions.

Ask whether the pattern suggests dehydration, whether a stool test is useful, which medicines should be paused or continued, and what fluids are appropriate for the person's age and health. Parents should clarify how to monitor feeding, alertness and wet nappies.