Adult diarrhoea and vomiting

General information

Usually vomiting and diarrhoea is caused by an acute gastroenteritis. The illness begins rapidly with severe vomiting and watery diarrhoea. Common symptoms include stomach cramps and high temperature. Vomiting or diarrhoea which starts suddenly usually gets better on its own in 1–3 days.


The most important treatment is hydration. You should drink frequently up to several litres of liquids throughout the day, even if you can only manage small portions at a time. To maintain a good electrolyte balance, drink salty liquids as well through the day.

You can eat something light and easy to digest, although eating may give you stomach cramps. Food is absorbed almost normally despite diarrhoea. Going without solid food for a couple of days is not harmful as long as you take a variety of fluids that contain energy (weak juice, water, tea and broth). Liquids are absorbed as normal despite diarrhoea. Milk-based, caffeinated drinks and artificial sweeteners are NOT recommended. You should also avoid energy drinks.

Try this recipe at home for diarrhoea: Mix 1 litre of fruit juice (preferably orange juice) with 1 litre of water and 1 teaspoon of salt. The natural sugar helps the water and salt to absorb. Special attention should be paid to sufficient hydration of the elderly and children, because they are not always able to say they are thirsty. If your urine is darker than normal, you may be dehydrated.

Over-the-counter medicines that slow down bowel movements as well as medicines that help with dehydration and salt imbalance (Floridal, Osmosal, lactic acid bacteria and the probiotic product Precosa) are available at pharmacies. Adults can take over-the-counter medicines for diarrhoea (e.g. Imodium), but follow the instructions on the package. Children should not be given diarrhoea medicines. Let the pharmacist help you choose the right type of medicine.

Vomiting and diarrhoea are usually highly contagious so maintaining meticulous hand and food hygiene is particularly important. Use hand sanitisers in addition to soap.

When should you seek medical advice?

Those who have been specifically advised to seek treatment more easily because of their long-term illness or medication, should do so. You should seek medical advice if

  • your symptoms include severe stomach pain
  • your symptoms began while abroad or soon after return from abroad
  • the diarrhoea/vomiting is very severe and you feel much worse than you usually do when sick
  • your temperature is higher than 38.5°C
  • there are clear signs of blood in your stools/vomit
  • your symptoms started while you were taking antibiotics

If the diarrhoea and vomiting has lasted longer than one week and you have had temperature for more than four days, you should seek medical advice.

This Self-care instruction has been produced in collaboration with Duodecim Terveyskirjasto

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Updated  5.6.2020