Diarrhoea - Lloydspharmacy.com Health

Reviewed by Dr Jeni Worden, GP

What is diarrhoea?

Diarrhoea is the passing of increased amounts (more than 300g in 24 hours) of loose stools.

It is often caused by a virus or bacteria and can be acute (short term) or chronic (long term) – lasting more than two to three weeks.

Most people are affected by diarrhoea at some time in their lives. It is often accompanied by stomach pains, feeling sick and vomiting.

It's usually due to consumption of drinking water contaminated with bacteria, undercooked meat and eggs or inadequate kitchen hygiene – in other words, an infection.

Diarrhoea normally only lasts for a few days, but it can be stressful when it occurs.

Globally, seven children die of diarrhoea every minute, mainly due to poor quality drinking water and malnutrition, which still affects the majority of the world population.

What causes diarrhoea?

Diarrhoea is mainly caused by bacterial and viral infections and food poisoning.
Diarrhoea can also be caused by bacteria or viruses that have been transmitted from person to person. For this reason, it is important to wash your hands with soap and water after using the toilet.
You cannot assess the quality of food or detect contamination by its smell or the way it looks. Food that is 'off' might be obvious, but contaminated food usually looks and tastes fine.

Diarrhoea occurs when the micro-organisms irritate the mucous membrane of the small or large intestine resulting in an abnormally large quantity of water in the motions.

The irritated gut becomes very active, contracting excessively and irregularly (colic). This can be accompanied by nausea, vomiting, and cold sweats. In some cases the motions may include some blood.

Food poisoning

Certain bacteria (usually staphylococci) irritate the digestive tract by producing toxins.

These toxins affect the mucous membrane much sooner, a few hours after consumption, compared with bacterial infection.

For this reason, people with inflammation or sores on their hands should not prepare food for others.

Other causes

When taking antibiotics, many people suffer diarrhoea, which may continue after the antibiotic course has finished.

The diarrhoea occurs because the antibiotic alters the intestinal bacterial environment. It is not an allergic reaction. In rare cases, such as diarrhoea caused by pseudomembranous colitis due to Clostridium difficile, it may require hospital admission.

This is an infection that can occur within two months of taking antibiotics or within a short time of being admitted to hospital.

Chronic diarrhoea

Chronic diarrhoea can be a symptom of many disorders:

irritable bowel syndrome
acute, recurrent or chronic intestinal infections
chronic intestinal inflammation (ulcerative colitis and Crohn's disease)
chronic pancreatitis, which produces fatty stools
laxatives
lactose intolerance
improper diet (consumption of too much alcohol, coffee or sweets)
metabolic disorders such as diabetes and thyrotoxicosis
intolerance to gluten (wheat protein).

What are the symptoms of diarrhoea?

Frequent, watery motions.
Loss of appetite.
Nausea, vomiting.
Stomach pains.
Fever.
Dehydration.

If the diarrhoea lasts more than three weeks, it is considered chronic.

What are the warning signs?

Blood in the motions.
Pus in the motions (yellow mucus).
Inability to drink liquids because of vomiting.
Dehydration - symptoms include excreting small amounts of dark urine, drowsiness, dry mucous membranes and thirst. Dehydration as a result of diarrhoea is a particular risk for young children and the elderly.
Pronounced drowsiness due to dehydration or intoxication.
Acute diarrhoea in infants.
Acute diarrhoea in very old people.

What can be done at home?

In cases of acute diarrhoea, it would be wise to drink more fluids (3 to 4 litres a day), preferably containing sugar and salts. Ready-mixed rehydration sachets (eg Dioralyte, Rehidrat) can be bought from the pharmacist and added to drinking water.
A sufficient intake has been obtained when the urine becomes light yellow in colour.
Eat something containing salt, such as crisps or soup.
Maintain good standards of hygiene.
Eat normally as soon as your appetite returns. But if you have suffered an acute attack of diarrhoea, avoid foods containing milk for a couple of days.

When should the doctor be consulted?

When one of the warning signs outlined above is present.
When the diarrhoea has occurred during or following a trip abroad – travellers' diarrhoea.
When the diarrhoea has lasted more than one to two weeks.

How is diarrhoea treated?

Diarrhoea can usually be treated safely 'at home' and normally goes away by itself within a week. Treatment with antibiotics is therefore rarely needed, and may cause side-effects, such as chronic diarrhoea.

Antidiarrhoeal agents, such as loperamide (eg Imodium), may be used, except in cases where there is blood or pus in the motions or if the diarrhoea is accompanied by high fever.

It has not been proven that freeze-dried lactic acid bacteria can prevent travellers' diarrhoea.

During visits abroad, boil all drinking water, or drink water from sealed bottles only. In addition, you should only eat vegetables that have been boiled or peeled and avoid ice-cream and salads (which may have been washed with unclean water).

Based on a text by Dr Torben Nathan, Dr Carl J Brandt and Dr Ove Schaffalitzky de Muckadell, professor of internal medicine

Last updated 01.12.2010

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