Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

Diarrhoea is when your poo becomes looser and more frequent than usual. It’s often caused by a stomach bug and you may experience vomiting too. It can be very uncomfortable and tiring, but should go away on its own in a few days.

What are the symptoms of diarrhoea?

Diarrhoea is when your poo becomes runnier and more frequent. Other symptoms that tend to happen at the same time include: 

  • Nausea and vomiting 

  • Bloating 

  • Cramps 

More serious symptoms that are important to look out for include: 

  • Blood or mucus in the poo

  • Weight loss 

  • Fever 

  • Lumps in your tummy

How long does diarrhoea last?

If a stomach bug is causing the diarrhoea, it will usually go away on its own within a couple of days. But it can last for up to a week. If yours has lasted longer, speak to a doctor who can help identify the cause. 

What causes diarrhoea?

1. An infection

A bowel or stomach infection (gastroenteritis) is the most common cause of diarrhoea in both children and adults. Causes of gastroenteritis include: 

  • Bacteria like campylobacter, E. coli, salmonella. Bugs like these are usually picked up from food that is contaminated.  

  • Viruses like norovirus or rotavirus 

  • Parasites like giardiasis. This is most commonly spread via contaminated water.

2. Medications 

Medications that can cause diarrhoea as a side effect include: 

  • Antibiotics 

  • Non-steroidal anti-inflammatory drugs (NSAIDs)

  • SSRIs (antidepressants) 

  • Statins 

  • Laxatives 

  • Chemotherapy drugs

3. Other conditions

Anxiety, food allergies, pregnancy, medications and long-term conditions like irritable bowel syndrome (IBS), coeliac disease inflammatory bowel disease (ulcerative colitis or Crohn's disease) can also be a cause of diarrhoea.

How do you treat diarrhoea?

Diarrhoea will usually go away on its own in a few days. Diarrhoea causes you to lose a lot of fluid, so it’s very important to stay hydrated. 

  • Drink plenty of fluids – this is particularly important for children who are at increased risk of dehydration

  • Stay at home until 48 hours after your symptoms have resolved 

  • Oral rehydration solutions (ORS) are available from the pharmacist if you’re worried about dehydration 

How can I prevent diarrhoea?

The most common cause of diarrhoea is an infection and therefore the best thing you can do is practise good hygiene and take care of yourself. 

  • Wash your hands with soap and water frequently 

  • Avoid sharing things such as towels, food and cutlery with other people 

  • Avoid contaminated water and undercooked food, particularly when travelling 

What is traveller’s diarrhoea?

Traveller’s diarrhoea is caused by eating contaminated food or drinking contaminated water, and is common when visiting new places. Bacteria are responsible for over 80% of cases. 

You likely have traveller’s diarrhoea if you’re away and have: 

  1. 3 or more runnier poos in 24 hours 

  2. Tummy pain, cramps, nausea, fever or vomiting 

Although it can be very unpleasant, traveller’s diarrhoea usually goes away without any medical treatment and isn’t usually serious. 

If you’re away and worried about diarrhoea, make sure to practise good personal hygiene and take care about what you eat and drink. You could also buy oral rehydration sachets before travelling. 

When should I speak to a doctor about diarrhoea?

If your diarrhoea is particularly severe and isn’t going away on its own, you should see a GP. 

If you have any of the following symptoms, speak to a doctor:

  • Signs of dehydration – drowsiness, not passing urine and dizziness 

  • Unexplained weight loss 

  • Persistent vomiting 

  • Lumps in your tummy

  • Very dark poo or blood, mucous or pus in the poo

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi