Fever with a stomach bug: what to know

Gastroenteritis irritates the stomach and bowel and may be caused by an infection. Fever can occur alongside nausea, abdominal cramps, loose stools, vomiting and reduced appetite. A fever does not by itself show which germ is responsible. Rotavirus infection is one possible cause, particularly in young children. Symptoms can make drinking difficult, while fluid loss from vomiting or diarrhoea can lead to dehydration.

Take frequent small sips of water or an oral rehydration drink. If vomiting settles, gradually return to light meals that you tolerate. Rest, wash hands carefully and avoid preparing food for other people while unwell. Record the temperature and note how often vomiting or diarrhoea occurs. Use fever medicine only as directed for your age and health; ask a pharmacist if you are unsure, especially if you are pregnant or treating a child.

Seek urgent help for confusion, fainting, severe weakness, trouble breathing, severe or localised abdominal pain, blood in vomit or stool, or inability to keep fluids down. Get medical advice if urination becomes much less frequent, the mouth is very dry, fever is persistent or symptoms are worsening. Babies, older adults and people with significant medical conditions can become dehydrated quickly and should be assessed promptly.

Ask what fluid replacement is suitable, whether your medicines need adjustment during vomiting or diarrhoea, and which changes should prompt same-day assessment.