Diarrhoea can cause frequent and urgent desires to go to the toilet. This is when the stool (faeces) is loose and watery.

Diarrhoea is passing looser or more frequent stools than is normal for you. It affects most people from time to time and is usually nothing to worry about. However, it can be distressing and unpleasant until it passes, which normally takes a few days to a week.

Sometimes people with diarrhoea are unable to reach a toilet in time and they become incontinent.

Symptoms

Frequently passing watery or loose poo. Some people may also have other symptoms, depending on the cause. Associated symptoms can include:

• stomach cramps
• nausea and vomiting
• headache
• loss of appetite

The excessive loss of water in your poo can also sometimes lead to dehydration, which can be serious if not recognised and treated quickly. Signs of dehydration in adults can include:

• tiredness and a lack of energy
• loss of appetite
• nausea
• feeling lightheaded
• dizziness
• dry tongue
• sunken eyes
• muscle cramps
• rapid heartbeat

Causes of short term diarrhoea

There are many different causes of diarrhoea, but a bowel infection (gastroenteritis) is a common cause in both adults and children. Gastroenteritis can be caused by:

• a virus – such as norovirus or rotavirus
  
• bacteria – such as campylobacter and Escherichia coli (E. coli), which are often picked up from contaminated food
  
• a parasite – such as the parasite that causes giardiasis, which is spread in contaminated water

These infections can sometimes be caught during travel abroad, particularly to areas with poor standards of public hygiene. This is known as travellers’ diarrhoea.

Diarrhoea can also be the result of anxiety, a food allergy, medication or a long-term condition, such as irritable bowel syndrome (IBS).

Other possible causes of short-term diarrhoea include:

• feelings of anxiety
• drinking too much alcohol
• a food allergy
• appendicitis
• damage to the lining of the intestines as a result of radiotherapy

Causes of long term diarrhoea

Conditions that can cause persistent diarrhoea include:

• Irritable bowel syndrome (IBS) – a poorly understood condition affecting the normal functions of the bowel
  
• Inflammatory bowel disease – conditions that cause the gut to become inflamed, such as Crohn’s disease and ulcerative colitis
  
• Coeliac disease – a digestive condition where you have an adverse reaction to gluten
  
• Chronic pancreatitis – inflammation of the pancreas
  
• Diverticular disease – where small bulges or pockets develop in the lining of the intestine
  
• Bowel cancer – this can cause diarrhoea and blood in your stools

Persistent diarrhoea can also sometimes occur following surgery on the stomach, such as a gastrectomy. This is an operation to remove part of the stomach – for example, as a treatment for stomach cancer.

Treatment

Diarrhoea will usually clear up without treatment after a few days, particularly if it’s caused by an infection. In adults, diarrhoea usually improves within two to four days, although some infections can last a week or more. While waiting for your diarrhoea to pass, you can ease your symptoms by following the advice outlined below.

It’s important to drink plenty of fluids to avoid dehydration, particularly if you are also vomiting. Take small, frequent sips of water.

Ideally, adults should drink a lot of liquids that contain water, salt and sugar. Examples are water mixed with juice and soup. If you are drinking enough fluid, your urine will be light yellow or almost clear.

Your GP or pharmacist may suggest using an oral rehydration solution to prevent dehydration if you’re at risk. Oral rehydration solutions usually come in sachets available from your local pharmacist without a prescription. They are dissolved in water and replace salt, glucose and other important minerals that are lost if you are dehydrated.

Prevention

Diarrhoea is often caused by an infection. You can reduce your risk by making sure you maintain high standards of hygiene. For example, you should:

• wash your hands thoroughly with soap and warm water after going to the toilet and before eating or preparing food
  
• clean the toilet, including the handle and the seat, with disinfectant after each bout of diarrhoea
  
• avoid sharing towels, flannels, cutlery or utensils with other household members
  
• It’s also important to practise good food and water hygiene while travelling abroad, such as avoiding potentially unsafe tap water and undercooked food.