Gastroenteritis
التهاب المعدة والأمعاء
Inflammation of the stomach and intestines, usually caused by a virus (sometimes called 'stomach flu') but occasionally by bacteria or parasites, leading to diarrhea, vomiting, abdominal cramping, and sometimes fever. Most cases resolve within a few days with rest and fluids; the main risk, especially in young children and older adults, is dehydration.
This information is for general awareness only and does not replace professional medical advice. Consult a doctor for diagnosis and treatment.
Quick answer
Gastroenteritis is inflammation of the stomach and intestines, usually caused by a virus (or sometimes bacteria or parasites). It causes diarrhoea and often vomiting.
Symptoms typically include watery diarrhoea, vomiting, stomach cramps, nausea and sometimes fever. Most healthy people recover within a few days.
Treatment focuses on staying hydrated — dehydration is the main danger, especially in babies, young children and older adults. Antibiotics are not needed for most cases. Seek medical care for signs of dehydration, blood in stools, high fever or symptoms that last more than a few days.
Symptoms
Watery diarrhoea
Nausea and vomiting
Stomach cramps and pain
Low-grade fever
Headache and muscle aches
Loss of appetite
Signs of dehydration
Dry mouth, little or dark urine, thirst, dizziness, and in babies fewer wet nappies and sunken soft spot.
Symptom guides
Causes and risk factors
Causes
- Viruses — Norovirus and rotavirus are common causes; spread easily from person to person and by contaminated surfaces.
- Bacteria — For example Salmonella, Campylobacter or E. coli, often from contaminated food or water.
- Parasites — For example Giardia, from contaminated water.
Risk factors
- Close contact with someone who is ill
- Infants and young children, especially in nurseries
- Older adults and people with weakened immunity
- Travel to areas with limited sanitation
- Crowded settings such as schools and care homes
- Poor hand hygiene or unsafe food handling
How is it diagnosed?
Most cases are diagnosed from symptoms alone, without tests.
Clinical assessment
Symptoms, contacts, travel and food history; check for dehydration.
Stool tests
Considered when symptoms are severe or prolonged, there is blood in the stool, or after recent travel or antibiotic use.
Blood tests
May be used to check hydration and salts (electrolytes) in more severe cases.
Treatment
For most people, treatment is supportive and the illness settles by itself. The main aim is to replace lost fluid. Care for infants, older adults and people with other illnesses should be guided by a doctor.
Fluids and oral rehydration
Frequent small sips of water or oral rehydration solution, especially for children and older adults.
Continue eating when able
Return to normal food as appetite returns; breastfeeding or formula should continue in infants.
Rest and hygiene
Rest, careful handwashing and staying away from work, school or childcare until at least 48 hours after symptoms stop.
Antibiotics and anti-diarrhoea medicines
Usually not needed and not suitable in every case; use only on medical advice.
Some anti-diarrhoea medicines are unsuitable for young children or when there is blood in the stool or high fever.
When should you see a doctor?
Arrange a medical assessment if
- Symptoms lasting more than a few days
- Signs of dehydration that are not improving
- A baby or young child, an older person, or someone with a long-term illness
- Blood or mucus in the stool
- Recent travel abroad or recent antibiotic use
Seek urgent care if
- Very little or no urine, extreme thirst, dizziness or fainting
- Persistent vomiting so fluids can't be kept down
- High fever, severe abdominal pain, or a stiff or swollen abdomen
- A baby that is drowsy, floppy, or has a sunken soft spot
- Black or bloody stools, or vomiting blood
Prevention
Wash hands with soap
After the toilet, changing nappies and before preparing or eating food.
Handle and cook food safely
Drink safe water
Rotavirus vaccination for infants
Follow your national immunisation schedule.
Stay home while ill
To avoid passing it on.
Frequently asked questions
What is gastroenteritis?
It is inflammation of the stomach and intestines, causing diarrhoea and often vomiting, usually from a viral infection.
How long does gastroenteritis last?
Viral gastroenteritis commonly settles within a few days to a week. See a doctor if symptoms persist.
Is gastroenteritis contagious?
Yes, especially viral forms. It spreads through contact, contaminated surfaces, food and water. Good handwashing is the best protection.
Do I need antibiotics?
Usually not. Most cases are viral and antibiotics don't help. A doctor will decide if a bacterial infection needs them.
What should I drink?
Small frequent sips of water or oral rehydration solution. Avoid relying only on sugary drinks or undiluted juice.
When should a child see a doctor?
If they show signs of dehydration, are very young, have blood in the stool, high fever, persistent vomiting, or are unusually drowsy.
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Medical sources
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