What are the first signs of gastroenteritis?

Gastroenteritis is inflammation of the stomach and intestines, commonly caused by an infection. It often begins with feeling sick, followed by vomiting, loose or watery stools, cramping, and reduced energy. Read more about [Abdominal Pain](/symptoms/abdominal-pain/). Symptoms can appear together or develop over a short period.

In children, rotavirus is one possible cause; [Rotavirus Infection](/conditions/rotavirus-infection/) can spread readily between people. The illness can also pass through contaminated food, drink, hands, or surfaces.

Take small, frequent sips of water or [Oral Rehydration Therapy](/treatments/acute-and-urgent-care/oral-rehydration-therapy/), particularly after each episode of vomiting or diarrhoea. Continue breastfeeding if relevant, and return gradually to simple foods when appetite comes back. Wash hands with soap and avoid sharing towels.

Watch for dry mouth, intense thirst, dizziness, unusual sleepiness, or reduced urination. These can signal [Dehydration](/conditions/dehydration/), especially in babies, older adults, and people with other illnesses.

Seek urgent help for blood in the stool, severe abdominal pain, confusion, fainting, repeated vomiting, or inability to drink. Contact a clinician promptly if dehydration signs appear, symptoms are severe, or a vulnerable person is affected. Some people may need [IV Fluid Therapy](/treatments/acute-and-urgent-care/iv-fluid-therapy/).

How much fluid should I take, and which rehydration product is suitable? Could this be gastroenteritis or another infection? When should I arrange a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/), and how can I reduce spread at home?