On this page:
Symptoms of diarrhoea
Diarrhoea can be dangerous for babies and young children
Causes of acute diarrhoea
Causes of chronic diarrhoea
Diagnosis of diarrhoea
Treatment for diarrhoea
Risk of spreading infection
Dietary adjustments may help diarrhoea
Where to get help
Things to remember
Food nutrients are absorbed in the small intestine. The waste is pushed into the large intestine (bowel) where water is removed. The resulting faeces is stored temporarily within the ****** then passed out of the body through the ****. Faeces are usually firm, moist and easy to pass. Diarrhoea is the frequent passing of loose, watery and unformed faeces.

Acute diarrhoea is the sudden onset of three or more loose stools per day, lasting less than 14 days. The most common cause of acute diarrhoea is an infection of the intestines, such as gastroenteritis or food poisoning. Viruses are responsible for most cases. The intestinal lining becomes irritated and inflamed, which hinders the absorption of water from food waste. In severe cases, the intestinal lining may even leak water.

Generally, acute diarrhoea resolves after a day or two. Chronic diarrhoea, which lasts four weeks or more, can be caused by a range of conditions that affect the intestines, including inflammatory bowel disease (IBD).
Symptoms of diarrhoea
The symptoms associated with diarrhoea include:
abdominal cramps
abdominal pains
urgency to go to the toilet
frequent passing of loose, watery faeces
nausea
vomiting.
Serious symptoms of diarrhoea
In most cases, acute diarrhoea is self-limiting and will resolve by itself within a day or two.
However, contact your doctor immediately if you experience serious symptoms including:
blood in the faeces
pus in the faeces
painful passage of faeces
repeated vomiting
inability to increase fluid intake
reduced or absent urination
fever (temperature greater than 38 ºc).
If you have a serious chronic medical condition, such as kidney or heart failure, even one day of diarrhoea can be dangerous. It’s safer to see your doctor as soon as possible.
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Diarrhoea can be dangerous for babies and young children
Acute diarrhoea can be life threatening to babies and young children. This is because their smaller bodies are more vulnerable to dehydration. If your baby or young child develops diarrhoea, seek medical attention straight away.
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Causes of acute diarrhoea
A bout of diarrhoea can be caused by a wide range of disorders, infections and events including:
food poisoning
gastroenteritis
tropical diseases, such as typhoid and cholera
anxiety or emotional stress
overconsumption of alcohol
medications, particularly antibiotics.
Common infectious agents
Contaminated food and water are common causes of acute diarrhoea. Some of the infectious agents known to cause diarrhoea include:
viruses – such as calici virus, adenovirus and rotavirus
bacteria – such as E. coli, Campylobacter, V. cholerae, Shigella, Salmonella and Staphylococcus aureus
parasites – such as Giardia lamblia, Cryptosporidium parvum and tapeworm.
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Causes of chronic diarrhoea
Some of the causes of chronic diarrhoea include:
coeliac disease – which reduces the intestine’s ability to absorb food
chronic constipation – the bowel is blocked by hard, impacted faeces, but some liquids manage to seep past the blockage. this condition, called ‘spurious’ or ‘overflow’ diarrhoea, is more common in the elderly
hormone disorders – such as diabetes or hyperthyroidism (overactive thyroid gland)
cancer – such as bowel cancer
inflammatory bowel disease – including ulcerative colitis and Crohn’s disease
irritable bowel syndrome – symptoms include abdominal pain, bloating, and alternating constipation and diarrhoea
lactose intolerance – the inability to digest the milk sugar lactose
medications – including antibiotics, antacids that contain magnesium, laxatives, and drugs for treating hypertension (high blood pressure) and arthritis.
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Diagnosis of diarrhoea
Successful treatment depends on diagnosing the cause. Investigations may include:
medical history
physical examination
blood tests
laboratory analysis of stool sample
colonoscopy (the insertion of a slender instrument into the **** so that the doctor can look at the bowel lining).
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Treatment for diarrhoea
Always see your doctor if you experience serious symptoms. Babies and young children with diarrhoea need prompt medical attention.
Treatment for diarrhoea depends on the cause, but may include:
plenty of fluids to prevent dehydration
oral rehydration drinks to replace lost salts and minerals. These drinks are available from pharmacies. An alternative is one part unsweetened pure fruit juice diluted with four parts of water
intravenous replacement of fluids in severe cases
medications such as antibiotics and anti-nausea drugs
anti-diarrhoeal medications, but only on the advice of your doctor. If your diarrhoea is caused by infection, anti-diarrhoeal drugs may keep the infection inside your body for longer
treatment for any underlying condition, such as inflammatory bowel disease.