Gastroenteritis

An infection of the stomach and bowel that causes diarrhoea and vomiting. It usually gets better in a few days.

InfectionDigestionLast updated: 21 October 2026

Quick Summary

Primary Symptoms

Diarrhoea, vomiting, tummy cramps, nausea and sometimes fever.

Common Treatments

Drinking plenty of fluids and ORS to prevent dehydration, rest, and zinc for children with diarrhoea.

Risk Factors

Contaminated food or water, close contact with infected people, poor handwashing and young age.

OverviewSymptomsCausesTreatmentFAQ

Overview

Gastroenteritis (stomach flu) is usually caused by viruses such as norovirus and rotavirus, but bacteria and parasites can also cause it.

The main danger is dehydration, especially in babies, young children and older people. Most people recover within a few days.

Symptoms

Diarrhoea

Loose, watery stools several times a day.

Vomiting and nausea

Often in the first day or two.

Tummy cramps

Pain that comes and goes.

Dehydration

Very little urine, dry mouth, sunken eyes, drowsiness or dizziness need urgent care.

Causes & Risk Factors

Biological Causes

Infection of the gut lining by viruses, bacteria or parasites, picked up from contaminated food, water, hands or surfaces.

Key Risk Factors

  • Food and water Eating contaminated or undercooked food and drinking unsafe water.
  • Close contact Spread easily in homes, schools and hostels.
  • Young and old age Babies and older adults dehydrate more quickly.

Management & Treatment

01. Rehydrate

Drink ORS and fluids in small, frequent sips. Keep breastfeeding babies.

02. Eat when ready

Return to normal food as soon as you feel able.

03. Zinc for children

Zinc supplements for 10 to 14 days help children recover from diarrhoea.

Frequently Asked Questions

Do I need antibiotics?
Usually not. Most cases are viral and get better without them.
When should I see a doctor?
For blood in stool, high fever, signs of dehydration, or diarrhoea lasting more than a few days.
How do I stop it spreading?
Wash hands with soap after using the toilet and before eating or cooking.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.