Beginning symptoms of stomach flu

Stomach flu is a common name for gastroenteritis, inflammation of the stomach and intestines, usually caused by an infection. Vomiting and diarrhoea can appear together or one may come first. Abdominal pain may feel cramp-like and come in waves. Rotavirus infection is one possible cause, particularly in young children. Symptoms can overlap with food poisoning, medication effects, or other illnesses, so the pattern and any exposure history help a clinician assess the cause.

Take frequent small sips of water or an oral rehydration drink, especially after vomiting or loose stools. Once fluids stay down, try simple foods in small amounts and return gradually to a normal diet. Rest, wash hands carefully, and avoid preparing food for others while unwell. Monitor urine, thirst, dizziness, and alertness because these can change as dehydration develops. Avoid sharing utensils and clean frequently touched surfaces.

Get urgent medical help for severe or worsening abdominal pain, blood in vomit or stool, confusion, fainting, breathing difficulty, or inability to keep fluids down. Seek prompt advice for signs of dehydration such as very little urine, a dry mouth, unusual sleepiness, or dizziness when standing. Babies, older adults, pregnant people, and those with long-term conditions may need earlier assessment.

Ask how much fluid to take, whether your medicines need adjustment, which foods are suitable, and what changes would mean you need same-day care.