Diarrhoea, which is watery, loose stools more than three times a day, is a very common complaint. It can be unpleasant and inconvenient but, in most cases, there’s no need to worry about diarrhoea.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023


Diarrhoea is often caused by a stomach bug (gastroenteritis) and passes after a few days. Most people have diarrhoea now and then.

A sudden (acute) bout of diarrhoea can usually be relieved with rest and fluids. If you, or your child, have frequent, persistent (chronic) diarrhoea, it might be a symptom of an underlying condition.

Symptoms of diarrhoea

The main symptom of diarrhoea is watery, loose stools more than three times a day. Other common symptoms include:

Diarrhoea can also result in dehydration.

Symptoms of dehydration

Symptoms of dehydration in children can differ from symptoms in adults. In children, common symptoms include:

  • Cold hands and feet
  • Drowsiness and/or irritability
  • Looking unwell
  • Not passing urine as often as usual
  • Pale or mottled skin

In adults symptoms of dehydration include:

  • A dry tongue 
  • Feeling tired, lightheaded and/or dizzy
  • Nausea and/or a loss of appetite
  • Muscle cramps
  • Rapid heartbeat
  • Sunken eyes

Causes of diarrhoea

Acute diarrhoea

You may not be able to pinpoint the exact cause of instant and unexpected diarrhoea. However, diarrhoea – and vomiting – is often your body’s way of getting rid of a stomach bug. This is a common cause of diarrhoea in both children and adults. 

A stomach bug could be caused by food poisoning. This occurs when food or drinks are ingested that are contaminated with harmful microorganisms, including: 

  • Viruses, such as norovirus or rotavirus
  • Bacteria, such as campylobacter and E. coli 
  • Parasites, such as Giardia 

Food poisoning is quite common if you’re visiting a developing country due to contaminated food or drinks — this is known as travellers’ diarrhoea. 

Other causes of acute diarrhoea include: 

  • Anxiety
  • Appendicitis
  • Drinking too much alcohol
  • Food allergies
  • Radiotherapy that damages the lining of the gut

Chronic diarrhoea

Frequent, long-term diarrhoea can be caused by:

  • Certain medications — this includes antacids that contain magnesium, antibiotics, cancer drugs, laxatives, NSAIDs (non-steroidal anti-inflammatory drugs), SSRIs (selective serotonin reuptake inhibitors) and statins
  • Complications after surgery 
  • Conditions affecting the digestive system — this includes bile acid malabsorption (BAM), chronic pancreatitis, coeliac disease, Crohn’s disease, diverticular disease, irritable bowel syndrome (IBS), some cancers and ulcerative colitis
  • Food intolerances, such as lactose intolerance
  • PMS
  • Stress, anxiety and migraines

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

Getting a diagnosis for diarrhoea

Usually, acute diarrhoea will pass in a week and without needing to see a GP. However, you should make sure that you remain at home for at least 48 hours after your last episode of diarrhoea. This will help prevent the spread of any infection that was causing your diarrhoea. 

If your child has diarrhoea, you should contact your GP urgently if they have any of the following symptoms: 

  • A fever
  • A severe or continuous stomach ache
  • Both diarrhoea and vomiting 
  • Blood in their stools
  • Signs of dehydration
  • Six or more episodes of diarrhoea in 24 hours

You should also contact your GP if you, or your child, have:

  • A very painful stomach or anal pain
  • Become severely dehydrated — look out for confusion, lightheadedness, a racing heartbeat and darkly-coloured urine
  • Been vomiting and can’t keep fluids down
  • Loose stools for seven days or more, very dark loose stools, diarrhoea with blood, or bowel incontinence
  • Unintentionally lost a lot of weight

Other situations when you should contact your GP include if your sleep or your child’s sleep is being disrupted by having diarrhoea at night and if you or your child have recently been treated in a hospital or taken antibiotics. 

You should also see your GP if you are experiencing symptoms of diarrhoea and meet any of the following criteria: 

  • Are elderly
  • Have an underlying health condition, such as diabetes, epilepsy, inflammatory bowel disease or kidney disease
  • Have a weakened immune system

Your GP will examine your stomach and may suggest treatment for diarrhoea, vomiting and/or dehydration. They may ask what and where you’ve eaten, if you’ve been abroad and what your stools look like. They may also ask if you have: 

  • Any other symptoms, such as a fever
  • Been in close contact with anyone who has diarrhoea
  • Been stressed or anxious recently
  • Taken any medication or changed your medication recently 

If you have chronic diarrhoea, your GP will advise you on how to stop diarrhoea and how to relieve your symptoms. Your GP will also discuss your symptoms with you and examine your stomach. 

To diagnose or rule out certain conditions, they may ask for a stool sample, particularly if you have a weakened immune system, recently travelled abroad, been treated in a hospital or taken antibiotics. Other symptoms that may need a stool sample to be collected include: 

  • Blood or pus in your stools 
  • Diarrhoea that has lasted for over two weeks
  • Whole-body symptoms, such as fever or dehydration

Your GP may also recommend other tests, including:

  • A rectal examination — this is more likely if you’re over 50
  • A sigmoidoscopy or colonoscopy — filming your digestive system using a flexible tube with a camera attached
  • Blood tests

If necessary, your GP will refer you to a gastroenterologist (a doctor specialising in the stomach and digestion) for diagnosis and treatment of the underlying cause of your diarrhoea.

Treatments for diarrhoea

Acute diarrhoea usually clears up without treatment. However, it can cause dehydration, which can be serious, especially for babies, young children and the elderly.

To reduce the risk of dehydration, it’s important to take sips of fluids throughout the day until your diarrhoea stops. Your pharmacist can recommend oral rehydration sachets, particularly if you are frail or elderly. These sachets are dissolved in water and replace lost salt, glucose and other minerals.

To ease diarrhoea symptoms, try taking it easy for a few days and:

  • Drink lots of fluids to maintain hydration levels — water, diluted squash and soup are good choices but avoid sugary and carbonated drinks
  • Eat small, light meals — avoid spicy, fried or rich foods
  • Relieve headaches and fever with pain relief such as ibuprofen
  • Work your way up to eating solid foods as soon as you can — good foods to eat while recovering from diarrhoea include bananas, boiled vegetables, potatoes and rice
  • Wash your hands regularly to help prevent passing on the infection or being reinfected

If your baby has diarrhoea and they are not fully weaned, continue feeding them breast milk or formula milk as normal. If your child has diarrhoea, avoid giving them fruit juice or fizzy drinks as these can worsen their diarrhoea.

If your diarrhoea continues or is very severe, your GP may suggest anti-diarrhoeal medication or, very occasionally, prescribe antibiotics. However, in most cases, medication is not needed and is usually not suitable for children. If you’re severely dehydrated, your GP may recommend inpatient treatment in hospital.

Once the underlying cause of your chronic diarrhoea has been identified, your doctor will provide the appropriate treatment:

  • Bile acid malabsorption can be treated with medication 
  • Coeliac disease can be treated by removing gluten from your diet
  • Inflammatory bowel disease can be treated with medication
  • Irritable bowel syndrome can be treated with dietary changes and medication

Complications of diarrhoea

Diarrhoea can lead to several complications, including: 

  • Contraceptive medications and medications for other conditions, such as diabetes and epilepsy, becoming less effective 
  • Dehydration
  • Haemolytic uraemic syndrome
  • Infection spreading to other areas of your body
  • Irritable bowel syndrome
  • Lactose intolerance 

Preventing diarrhoea

The most common cause of diarrhoea is an infection. Practising good personal hygiene can, therefore, reduce your risk of catching diarrhoea and of reinfection. Make sure you: 

  • Avoid sharing items with other people you live with — eg cutlery, flannels, towels and other utensils
  • Clean your toilet with disinfectant after every episode of diarrhoea
  • Wash any soiled clothing or bedding at a high temperature, separately from your other clothes 
  • Wash your hands properly with soap and water before eating or making food and after going to the toilet 
  • Remain at home for at least 48 hours after your last episode of diarrhoea
  • Avoid swimming pools for at least two weeks after your last episode of diarrhoea

Food hygiene is also important to prevent diarrhoea. Make sure you:

  • Never eat food that is past its use-by date
  • Never keep cooked and raw foods together
  • Properly refrigerate foods
  • Properly cook food all the way through
  • Regularly clean food preparation surfaces, cutlery and utensils with hot soapy water

To prevent travellers' diarrhoea, be aware of whether you're travelling to a country where public hygiene standards are low. If so, make sure you avoid: 

  • Drinking tap water
  • Drinking or eating unpasteurised dairy products
  • Eating ice cream, salads, raw or undercooked food, food containing undercooked eggs, and fruits and vegetables with damaged skin

Frequently asked questions

How can I stop diarrhoea?

Diarrhoea usually clears up without any treatment but you may experience dehydration. It is, therefore, important to drink lots of fluids, such as water, diluted squash and soup. Avoid sugary and carbonated drinks, as well as spicy, fried or rich foods. Also, make sure you wash your hands regularly to help prevent reinfection — infection with a virus or bacteria is the most common cause of diarrhoea. If your diarrhoea is severe or keeps returning, see your GP for treatment.

How long should diarrhoea last in adults?

Diarrhoea in adults usually stops in 5-7 days without any treatment. If your diarrhoea persists, you experience symptoms of dehydration (confusion, lightheadedness, a racing heartbeat and darkly-coloured urine), or have been vomiting for more than two days, see your GP.

Frequent, long-term diarrhoea (chronic diarrhoea) can last for several weeks at a time. It can be a sign of an underlying condition and you should, therefore, see your GP.

What is the main cause of diarrhoea?

The most common cause of diarrhoea is an infection with harmful microorganisms. This includes viruses, such as norovirus or rotavirus, bacteria, such as campylobacter and E. coli, and parasites, such as Giardia.

When should I be concerned about diarrhoea?

If your diarrhoea is severe or occurs frequently (chronic diarrhoea), you should see your GP. You should see your GP if you:

Experience loose stools for seven days or more, very dark loose stools, diarrhoea with blood, or bowel incontinence
Become severely dehydrated
Experience a very painful stomach or anal pain
Unintentionally lose a lot of weight
Have been vomiting and can’t keep fluids down
Have a fever

What is watery diarrhoea a sign of?

Watery diarrhoea is a sign that you might have a stomach bug (gastroenteritis). This is caused by an infection with a virus, such as norovirus or rotavirus, bacteria, such as campylobacter and E. coli, or a parasite, such as Giardia. Contaminated food and water are common sources of infection.

How long does it take for stool to go back to normal after diarrhoea?

Diarrhoea in adults usually stops in 5-7 days and your stools should return to normal after this. If you continue to have loose stools after seven days, see your GP.

If you have chronic diarrhoea, your stools can remain loose for several weeks and you should see your GP to find out if you have an underlying condition that needs treatment.