Gastroenteritis is an infection of the stomach and bowel. The most common symptoms are repeated episodes of diarrhoea (three or more episodes within the space of 24 hours) and vomiting.
These pages focus on gastroenteritis in adults. For information on childhood (rotavirus) gastroenteritis, see the Health A-Z topic on Gastroenteritis in children
How common is gastroenteritis?
Gastroenteritis is very common: approximately 1 in 5 people are affected by the condition in England every year.
Gastroenteritis can be caused by a virus such as the norovirus, or by a number of different types of bacteria. Typically, bacterial gastroenteritis develops as a result of food poisoning.
How gastroenteritis is spread
Most forms of gastroenteritis are highly infectious. The condition is mainly spread through what is known as the faecal/oral route - when bacteria found in faeces (stools) are transferred to your mouth.
Bacteria can be transferred this way through poor hygiene. For example, if someone does not wash their hands after going to the toilet, any viruses or bacteria on their hands will be transferred to whatever they touch, such as a glass, kitchen utensil or food. If you touch this contaminated object then touch your face, or if you eat contaminated food, you may swallow some of the viruses or bacteria. This causes the symptoms of gastroenteritis.
If you have gastroenteritis, do not return to work until 48 hours after passing a normal (solid) stool.
Outlook
Most people with gastroenteritis have only mild symptoms, and the condition improves within a few days without the need for treatment.
However, if symptoms are severe, or the person is vulnerable because of their age or because of another illness, hospital treatment may be required. This is because diarrhoea can make a person become quickly dehydrated, which can be fatal in severe cases.
There are an average of 190 deaths caused by gastroenteritis each year in England and Wales. Most of these deaths occur in people aged over 65.
Antibiotics
Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. For example amoxicillin, streptomycin and erythromycin.
Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some others are good for you.
Diarrhoea
Diarrhoea is the passing of frequent watery stools when you go to the toilet.
Stomach
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.
