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Gastroenteritis- Causes, Symptoms and Treatment

What is gastroenteritis?

Gastroenteritis is the irritation and inflammation of the lining of the stomach and intestine usually due to infection – sometimes referred to as a stomach bug.

Some vulnerable groups, for...

What is gastroenteritis?

Gastroenteritis is the irritation and inflammation of the lining of the stomach and intestine usually due to infection – sometimes referred to as a stomach bug.

Some vulnerable groups, for example young children, the sick, those with long term medical conditions and the elderly, will need medical advice if they start to experience symptoms of gastroenteritis. You should also seek medical advice if you:

  • experience fever
  • have blood in your stool
  • have persistent diarrhoea (more than 7 days for an adult). If you are considering taking Imodium, seek medical advice first if your diarrhoea has lasted for more than 48 hours.
  • are vomiting a lot and can’t keep fluids down
  • can’t control your bowels
  • have signs of dehydration
  • have recently travelled abroad
  • don’t have someone who can look after you at home and your symptoms are severe

What are the Causes of Gastroenteritis?

Gastroenteritis is usually caused by a viral or bacterial infection. Some common causes are:

Norovirus is a stomach bug that causes vomiting and diarrhoea, most commonly in the winter months.

Travellers’ diarrhoea and food poisoning are caused by consuming contaminated food or water.

What are the Symptoms of Gastroenteritis?

The time between catching the infection and experiencing symptoms depends on the type of infection you have but is usually between one and three days.

If you have gastroenteritis, as well as diarrhoea, you are likely to also experience:

  • nausea
  • vomiting
  • headaches
  • fever

Is Gastroenteritis Contagious?

If gastroenteritis is caused by a virus such as norovirus, it will be highly contagious. People infected with norovirus can spread the virus from the day they start to feel ill to at least three days after diarrhoea or vomiting stops. It is therefore important to rest and stay at home for 48 hours after the resolution of symptoms.

Some ways to prevent spreading gastroenteritis include:

  • ensure you wash your hands frequently and thoroughly with soap and water, particularly after using the toilet and before preparing food. Don't rely on alcohol hand gels, as they're not always effective
  • disinfect surfaces or objects that could be contaminated. It's best to use a bleach-based household cleaner
  • wash contaminated items of clothing or bedding separately on a hot wash
  • don’t share towels, flannels, cutlery or utensils while you are ill
  • flush away any poo or vomit in the toilet or potty and clean the surrounding area
  • practice good food hygiene (read more tips below)

How long does Gastroenteritis last?

If gastroenteritis is caused by norovirus, then symptoms usually begin 24–48 hours after you are first exposed to the virus, but they can appear as early as 12 hours afterwards.

The symptoms may last for a day or two but can persist for as long as 10 days.

Food and Gastroenteritis

Gastroenteritis can also be caused by eating food that has not been prepared or stored safely, causing food poisoning. The Food Standards Agency (FSA) recommends remembering the "four Cs"- Cleaning, Cooking, Chilling and avoiding Cross Contamination.

  • You can prevent the spread of gastroenteritis by maintaining good personal hygiene standards and keeping work surfaces and utensils clean. See more information above.
  • It is important to cook food thoroughly, particularly meat and most types of seafood.
  • When reheating food, ensure it is steaming hot all the way through. Don't reheat food more than once.
  • Certain foods need to be kept at the correct temperature to prevent harmful bacteria from growing and multiplying. Always check the storage instructions on the label.
  • If food must be refrigerated, make sure your fridge is set to 0–5C (32–41F).
  • Cooked leftovers should be cooled quickly, ideally within a couple of hours, and put in your fridge or freezer.
  • Always wash your hands after handling raw food
  • Store raw and ready-to-eat foods separately. Store raw meat in sealable containers at the bottom of your fridge so that it cannot drip onto other foods
  • Use a different chopping board for raw food and ready-to-eat food, or wash it thoroughly in between preparing different types of food
  • Clean knives and other utensils thoroughly after using them with raw food
  • Do not wash raw meat or poultry – any harmful bacteria will be killed by thorough cooking, and washing may splash harmful bacteria around the kitchen
  • Never eat food that is past its use by date

Gastroenteritis whilst travelling

Minimise your risk of developing gastroenteritis when travelling by:

  • eating at places with a good hygiene reputation
  • choosing food that is served piping hot
  • avoiding raw vegetables and salads or food that has been left out in the heat
  • avoiding ice (unless you know it is made from clean water)
  • drinking water and other drinks from bottles only (with an intact seal), or using a reliable filter and boiling the water

Before travelling abroad, plan what you can take with you in case you become ill. If you have any questions or concerns, talk to your travel health adviser, GP or pharmacist before you go abroad.

Treatment of Gastroenteritis

Stay hydrated! Make sure that you drink lots of fluids, such as water to help to rehydrate you.

Oral rehydration solutions can help your body to replace lost fluid. These typically come as a powder that you add to water to make a drink to help replace the sugar, salts and minerals you have lost.

If you have short-term diarrhoea, IMODIUM® can provide relief from diarrhoea within one hour. IMODIUM® works in harmony with your body to help restore its natural rhythm.

If you have severe diarrhoea, blood in your stools or a high temperature, or if your symptoms persist for more than 48 hours, consult your doctor before using any OTC medicine such as Imodium.

Discover more about how Imodium® works here. Always read the label.

This page was last updated in January 2019

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