Diarrhoea

Written by Ellen Lees
Ellen Lees
Nutritionist Resource Content Team

Last updated 3rd August 2026 | Next update due August 2029

Diarrhoea describes passing loose or watery stools, or needing to go to the toilet more often than usual. While it can be unpleasant and sometimes worrying, most cases improve within a few days without medical treatment. Understanding the causes of diarrhoea and the role diet and hydration can play in managing your symptoms can help you feel more in control and know when it's time to seek support.

On this page, we'll explain what can cause diarrhoea, which foods and drinks may help or worsen your symptoms, when to speak to your GP, and how a nutritionist can support you if your symptoms are ongoing or linked to an underlying digestive condition.

What is diarrhoea and what causes it?

In the UK, diarrhoea is very common and usually not a cause for concern. It is a term used to describe loose stools that are often a symptom of a bowel infection. This can be contracted through contaminated food, water or spread through illness.

While most cases of diarrhoea improve within a few days, dehydration can become serious if fluids aren't replaced, particularly in babies, young children and older adults. A stomach bug or food poisoning are two of the most common causes of diarrhoea. 

Diarrhoea is one of the most common symptoms of a digestive problem. While there are many causes of diarrhoea, gastroenteritis is the most common. Gastroenteritis (bowel infection) is commonly caused by:

  • Bacteria such as Escherichia coli (E. coli). This is often transferred through eating contaminated food.
  • A virus caught through other people, such as norovirus.
  • Parasites such as giardiasis, which can be picked up through consuming contaminated water.

These infections can be caught while travelling abroad. Diarrhoea can also be the result of a food allergy, medication, stress and anxiety or a condition such as irritable bowel syndrome (IBS).

Common symptoms include:

  • Loose, watery stools
  • Headache
  • Bloating
  • Lower abdominal pain
  • Nausea
  • Loss of appetite
  • Weight-loss

Most people will experience diarrhoea at some point in their lives, and normally it will clear up after a few days. However, it can lead to dehydration, so it is important for you to ensure you are drinking water regularly. It is particularly important to ensure babies and young children do not become dehydrated when experiencing diarrhoea. 

If you have frequent diarrhoea or you are experiencing symptoms for longer than a week, it is recommended you visit your GP.

Diarrhoea in children

It can be worrying if your child has diarrhoea. Children of any age can catch a virus or bacteria-related infection. If they appear dehydrated, are vomiting or have had more than six episodes of diarrhoea in one day, it is advised you contact your GP.

If the child is between one and five, the loose, watery stools should have subsided within five to seven days and very seldom persist beyond two weeks. Be sure to give your child plenty of water (even if they are vomiting) to ensure they do not become dehydrated.


What should you eat when you have diarrhoea?

A balanced diet is particularly important in maintaining the health of the digestive system. But when you have loose stools, it can be difficult to know what to eat, what to avoid and whether to eat at all. For example, while a high-fibre diet is usually recommended for lowering cholesterol and maintaining bowel regularity, it can make some cases worse.

When experiencing diarrhoea, it is recommended that certain foods be avoided until symptoms improve. It is advisable that you discuss the condition with a GP before making any dietary changes.

What foods should you avoid with diarrhoea?

  • High-fibre cereals such as bran flakes
  • Fatty or fried foods
  • Pickled or spicy foods
  • Caffeine and alcohol
  • Fruit juice or fizzy drinks

What is a diarrhoea diet?

When experiencing diarrhoea, many experts suggest eating solid food as soon as you feel you can. It is recommended that you eat small, light meals throughout the day. 

If you are struggling to eat or are vomiting after eating, ensure you stay hydrated. One of the most important treatments for diarrhoea is avoiding dehydration. You need to replace the nutrients you have lost. While sipping regularly on water is vital, it is important to consume fluids that replace the sugar, salt and potassium that have also been lost as a result of diarrhoea.


How is diarrhoea treated?

When waiting for the virus to pass, it is important to continue drinking fluids and to eat when you can. If you have signs of dehydration, are an older person, have a weakened immune system or other health conditions that may increase your risk of dehydration, or need to stop diarrhoea for a few hours, speak with a pharmacist. They may be able to recommend over-the-counter medication for those over the age of 12, including rehydration powder. 


When should I see my GP about diarrhoea?

Diarrhoea is often a symptom of a bowel infection after contracting a virus or bacteria through food, water or travelling abroad. While this form of diarrhoea will often clear up after two to three days, some people will experience loose stools more frequently.

Persistent diarrhoea could be the result of a range of conditions, including:

Diarrhoea may also be a side effect of an allergy or any medication you are taking, such as antibiotics or laxatives. If you are concerned or your diarrhoea is lasting for longer than a week, it is advised you speak to your GP.

How is the cause of diarrhoea diagnosed?

If you wish to visit your GP, you may be asked a series of questions regarding your bowel movements and your health. These may include:

  • How often do you experience symptoms?
  • Have you dined out or travelled abroad recently?
  • Have you been feeling stressed or anxious?
  • Are you taking any medication?

Depending on your symptoms, your GP may also require you to provide a stool sample, a blood sample, or you may need to undergo a rectal examination. These may be needed in order to test for any underlying conditions.


How can a nutritionist help with diarrhoea

Living with frequent diarrhoea can affect everyday life, making it difficult to feel confident at work, socially or when travelling. You don't have to manage ongoing symptoms alone. Those who experience frequent diarrhoea may feel helpless, isolated and embarrassed to admit the problem. If you are diagnosed with a condition such as IBS, coeliac disease or Crohn’s disease, a nutritionist may be able to help.

During the initial consultation, a nutritionist may ask you to explain your symptoms. This may include details about your bowel movements. While this can feel embarrassing, it is important to explain how you are feeling so that they can understand what triggers the problem. They may also ask you to complete a food diary each time you suffer from diarrhoea. This way, they can look at the food you eat, when you eat it, and whether the loose bowel movements are a symptom of an allergy or intolerance.

If the diarrhoea is a symptom of a long-term condition, a nutritionist will work with you to create a specialised diet plan. They will offer guidance and support so that you can regain a sense of control over the situation. Nutritionists can also offer support in the way of private laboratory testing such as stool tests and food intolerance/allergy tests.

A nutrition professional will know how detrimental conditions such as diarrhoea can be to quality of life and self-esteem and will do all they can to help you.


Living with diarrhoea

Living with diarrhoea can be an upsetting, frustrating and embarrassing time. If you are unwell, it can occur at any time, whether at work, at home or in public. It can often make a person feel helpless and out of control. The important thing to do when you have diarrhoea is to rest. It can be stressful and exhausting as you are losing fluid and often unable to eat much. 

If you are unwell, it is important to take some time out to recover and avoid spreading illness to others. Consider asking a friend or family member to help out with housework, the cooking or taking the children to school.

If the sudden urge to use the toilet is causing you anxiety, support is available. Learn more about toilet anxiety and what can help.


Further resources 

All content displayed on Nutritionist Resource is provided for general information purposes only, and should not be treated as a substitute for advice given by your GP or any other healthcare professional. 

Share this page with a friend
Ready to connect with a therapist?
Select a location below to explore practitioners in your area.

Cities

Counties

Countries

Would you like to provide feedback on our content?
Tell us what you think

Please note we are unable to provide any personal advice via this feedback form. If you do require further information or advice, please search for a professional to contact them directly.

You appear to have an ad blocker enabled. This can cause issues with our spam prevention tool. If you experience problems, please try disabling the ad blocker until you have submitted the form.

This site is protected by reCAPTCHA, the Google Privacy Policy and Terms of Service apply.
Image

Find a nutritionist dealing with diarrhoea

All nutrition professionals are verified

All nutrition professionals are verified