Gastroenteritis in adults 



Find out what norovirus is, how to reduce your risk of getting it and what to do if you have it.

Media last reviewed: 19/11/2012

Next review due: 19/11/2014

How common is gastroenteritis?

In England, gastroenteritis is very common, with about one in five people affected every year.

Gastroenteritis can be caused by a virus, such as the norovirus, or by a number of different types of bacteria. Bacterial gastroenteritis usually develops as a result of food poisoning.

Each year in England and Wales, an average 190 deaths occur because of gastroenteritis. Most deaths are in people over 65 years of age.

Gastroenteritis is an infection of the stomach and bowel.

The most common symptoms are vomiting and repeated episodes of diarrhoea (three or more episodes within 24 hours).

Read more about the symptoms of gastroenteritis.

The causes and treatment of gastroenteritis can differ between children and adults. This section is about gastroenteritis in adults. Read more about gastroenteritis in children.

What causes gastroenteritis in adults?

In England, the two most common causes of gastroenteritis in adults are the norovirus and food poisoning.

The infection interferes with one of the main functions of the intestines – the absorption of water from the contents of your intestines into the body.

This is why the most common symptom of gastroenteritis is watery diarrhoea and why dehydration (a lack of water in the body) is such a common complication.

Read more about the causes of gastroenteritis.

How gastroenteritis is spread

Most types of gastroenteritis are highly infectious. The condition is mainly spread when bacteria found in faeces are transferred to your mouth.

Bacteria can be transferred 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 the contaminated object and then touch your face, or if you eat contaminated food, you may become infected by the virus or bacteria. Once infected, you will have the symptoms of gastroenteritis, such as vomiting and diarrhoea.

If you have gastroenteritis, you should not return to work until 48 hours after passing a normal (solid) stool.

When to see your GP

In most cases, gastroenteritis does not need to be diagnosed because your symptoms should improve without treatment.

If your symptoms are severe or persist, your GP may take a stool sample so that it can be checked for specific bacteria or parasites. If a bacterium or parasite is identified, appropriate medication will be prescribed.

In some circumstances, blood tests and urine tests may be used to rule out other conditions, particularly if you are very unwell or if the symptoms last longer than usual.

Treating gastroenteritis

Most people with gastroenteritis only have mild symptoms and the infection passes after a few days without the need for treatment.

However, you may need treatment in hospital if your symptoms are severe, or if you are vulnerable because of your age or another illness. This is because diarrhoea can quickly cause dehydration which, if severe, can be fatal.

The dangers of dehydration mean that it is very important to replace fluids that are lost through vomiting and diarrhoea. You should drink at least 2 litres (3.5 pints) of water a day, plus 200ml (a third of a pint) of water after every episode of diarrhoea.

An oral rehydration solution can be used by people who are particularly vulnerable to the effects of dehydration, such as elderly people or those with another existing condition.

In severe cases of gastroenteritis, antidiarrhoeal medication or anti-emetics (anti-sickness medication) may be recommended.

Read more about treating gastroenteritis.

Preventing gastroenteritis

As gastroenteritis is highly infectious, it is important to take steps to prevent it from spreading to other people. These include:

  • washing your hands thoroughly after going to the toilet and before eating or preparing food
  • cleaning the toilet, including the handle and the seat, with disinfectant after each bout of vomiting or diarrhoea
  • not sharing towels, flannels, cutlery or utensils with other members of your household
  • not returning to work until 48 hours after your last bout of vomiting or diarrhoea

Read more about preventing gastroenteritis.

Page last reviewed: 10/05/2012

Next review due: 10/05/2014


How helpful is this page?

Average rating

Based on 622 ratings

All ratings

Add your rating


The 8 comments posted are personal views. Any information they give has not been checked and may not be accurate.

survivor84 said on 27 February 2013

Hi, I wonder if anyone could help.. I had Gastroenteritis at the beginning of the new year and unfortunately late last Sunday week went down with it again. So far I've been off from work over a week and a half now and remain on a gp fitness note until Monday. I do suffer from a Diverticular Disease and CFS but was wondering whether there was anything I could do to fasten up the recovery process? Obviously I'm concerned that I've already had a lot of time off over the past yearand don't want anymore due to this. Many thanks.

Report this content as offensive or unsuitable

sunbeampannotia said on 08 February 2013

I am down with it at the moment. Started with vomiting & severe lower abdominal pain 12 hours plater diarrhoea has started. Drinking loads of water even if its regurgitated doc gave me anti sickness tabs and haven't vomited for 2 hours!! Trying a slice of dry toast & marmite. Hope it's only a mild bout. Was going to a dinner & dance tomorrow but that's out the window!!! Never mind...... Could be worse.....sympathy with you fellow sufferers :)

Report this content as offensive or unsuitable

jamesAFC said on 08 October 2012

anyone help please about 3 weeks ago i came over all lightheaded felt like i wanted to be sick but nothing comeing up . after that to this date i get lightheded start burpin that makes me wona be sick. ache feelin in my lower right stumach. diarrhea that is ok ish at min . i have had a full blood count thats is ok apart from my biliruben been 34.5 . been docs and AE been told mite be gallstone then told mite be gastroentertis . now im just worrying what is wrong with me and it dont help as my dad past away on the 23rd of lung cancer. if any one can help be realy greatfull.

Report this content as offensive or unsuitable

LauraHunni12 said on 31 July 2012

I finally managed to get some tests done, and I was in fact diagnosed with a gastro-intestinal tract infection, and I was given antibiotics. I reacted really badly to them, and went back to the doctors after being told to go to see them if I was having serious side-effects. Apparently there's no other way to cure it. But they've never even said what type of gastro-intestinal tract infection I have.

I've been eating a lot better, but I've still lost a bit of weight.

I had to tell the doctors that I doubted it was Gastroenteritis otherwise it would have gone by now.

Report this content as offensive or unsuitable

Eastie said on 27 July 2012

Hi everyone - I can really sympathise with Laura and Mandy's daughter. I'm going through the same thing myself at the moment. I've had Gastroenteritis for 2 weeks and I've lost a stone. I have had to be off work due to daily diarrhea and cramps in my digestive area.
The Doc says it's Gastroenteritis but I think that is a rather vague 'catch-all' term. Obviously my stomach and small intestine are infected, but by what cause?

If it was a bug or food poisoning, then it would surely have disappeared by now. Like Laura, I can't eat - I do force myself to eat some cream crackers and veg soup. Anything else makes me extremely nauseous (within 1-2hours) and I'm either sick, have violent diarrhea, or both. I've had bad heartburn and acid reflux since the vomiting passed. I don't mean to moan - it's just, I'm confused.

Report this content as offensive or unsuitable

rosexelex said on 13 June 2012

Cure yourself by eating some Marmite, wholemeal bread and green vegetables as your system is deficient in the Vit B12 and cannot repair itself because the constant diarrhoea is preventing proper digestion and absorption of eseential nutrients.

Report this content as offensive or unsuitable

mandycharlizo said on 25 April 2012

Hi Laura, how do you feel now? My 14 year old daughter has been ill for the last 5 weeks, she has been told its gastroenteritis but i am like you, cannot understand why they don't do tests. She is still suffering from stomach cramps and nausea and wishes it would go away.

Report this content as offensive or unsuitable

LauraHunni12 said on 10 April 2012

This is funny. It says that hygiene is the best way to prevent it - not that it helped, I contracted it by being in the same room as someone who had it!

Also, I've had Gastroenteritis symptoms for nearly nine weeks now, minus the vomiting and diarrhea. The doctors won't run any tests on me despite it being an ongoing problem, and the weight has literally dropped off, seeing as though I barely have an appetite now.

It's better now than when it started, but the symptoms are still there. Why aren't I being tested?

Report this content as offensive or unsuitable

How to prepare and cook food safely

How to prepare and cook food correctly to reduce the risk of food poisoning, including E. coli

Symptom checker

If you have a health problem, our symptom checker can help you manage it or find out where to go for help

Find and choose services for Gastroenteritis