Key facts
Diarrhea disease is the second leading cause of death in children under five years old. It is both preventable and treatable. Everything you needed to know about diarrhea disease, how it spreads, and how dangerous it is to sensitive populations.
Each year diarrhea kills around 525 000 children under five.
A significant proportion of diarrhea disease can be prevented through safe drinking-water and adequate sanitation and hygiene.
Globally, there are nearly 1.7 billion cases of childhood diarrhoeal disease every year.
Diarrhea is a leading cause of malnutrition in children under five years old.
Diarrhea disease is the second leading cause of death in children under five years old, and is responsible for killing around 525 000 children every year. Diarrhea can last several days, and can leave the body without the water and salts that are necessary for survival. In the past, for most people, severe dehydration and fluid loss were the main causes of diarrhea deaths. Now, other causes such as septic bacterial infections are likely to account for an increasing proportion of all diarrhea-associated deaths. Children who are malnourished or have impaired immunity as well as people living with HIV are most at risk of life-threatening diarrhea.
Diarrhoea is defined as the passage of three or more loose or liquid stools per day (or more frequent passage than is normal for the individual). Frequent passing of formed stools is not diarrhoea, nor is the passing of loose, “pasty” stools by breastfed babies. Everything you needed to know about diarrhea disease, how it spreads, and how dangerous it really is too sensitive populations.
Diarrhea is usually a symptom of an infection in the intestinal tract, which can be caused by a variety of bacterial, viral and parasitic organisms. Infection is spread through contaminated food or drinking-water, or from person-to-person as a result of poor hygiene.

Interventions to prevent diarrhea, including safe drinking-water, use of improved sanitation and hand washing with soap can reduce disease risk. Diarrhea should be treated with oral re-hydration solution (ORS), a solution of clean water, sugar and salt. In addition, a 10-14 day supplemental treatment course of dispersible 20 mg zinc tablets shortens diarrhea duration and improves outcomes.
There are three clinical types of diarrhea:
- acute watery diarrhea – lasts several hours or days, and includes cholera;
- acute bloody diarrhoea – also called dysentery; and
- persistent diarrhoea – lasts 14 days or longer.
Scope of diarrhea disease
Diarrhea disease is a leading cause of child mortality and morbidity in the world, and mostly results from contaminated food and water sources. Worldwide, 780 million individuals lack access to improved drinking-water and 2.5 billion lack improved sanitation. Diarrhea due to infection is widespread throughout developing countries. Everything you needed to know about diarrhea disease, how it spreads, and how dangerous it really is too sensitive populations.
In low-income countries, children under three years old experience on average three episodes of diarrhea every year. Each episode deprives the child of the nutrition necessary for growth. As a result, diarrhea is a major cause of malnutrition, and malnourished children are more likely to fall ill from diarrhea.
Dehydration

The most severe threat posed by diarrhoea is dehydration. During a diarrhoeal episode, water and electrolytes (sodium, chloride, potassium and bicarbonate) are lost through liquid stools, vomit, sweat, urine and breathing. Dehydration occurs when these losses are not replaced.
The degree of dehydration is rated on a scale of three.
- Severe dehydration (at least two of the following signs):
- lethargy/unconsciousness
- sunken eyes
- unable to drink or drink poorly
- skin pinch goes back very slowly ( ≥2 seconds )
- Some dehydration (two or more of the following signs):
- restlessness, irritability
- sunken eyes
- drinks eagerly, thirsty
- No dehydration (not enough signs to classify as some or severe dehydration).
Causes
Infection: Diarrhea is a symptom of infections caused by a host of bacterial, viral and parasitic organisms, most of which are spread by faeces-contaminated water. Infection is more common when there is a shortage of adequate sanitation and hygiene and safe water for drinking, cooking and cleaning. Rotavirus and Escherichia coli, are the two most common etiological agents of moderate-to-severe diarrhea in low-income countries. Other pathogens such as cryptosporidium and shigella species may also be important. Location-specific etiologic patterns also need to be considered.

Children who die from diarrhea often suffer from underlying malnutrition, which makes them more vulnerable to diarrhea. Each diarrhea episode, in turn, makes their malnutrition even worse. Diarrhea is a leading cause of malnutrition in children under five years old.
Source: Water contaminated with human feces, for example, from sewage, septic tanks and latrines, is of particular concern. Animal feces also contain microorganisms that can cause diarrhea.
Other causes: Diarrhea disease can also spread from person to person, aggravated by poor personal hygiene. Food is another major cause of diarrhea when it is prepared or stored in unhygienic conditions.Unsafe domestic water storage and handling is also an important risk factor. Fish and seafood from polluted water may also contribute to the disease.
Prevention and treatment

Key measures to prevent diarrhea include:
- access to safe drinking-water;
- use of improved sanitation;
- hand washing with soap;
- exclusive breastfeeding for the first six months of life;
- good personal and food hygiene;
- health education about how infections spread; and
- rotavirus vaccination
Key measures to treat diarrhea include the following:
- Re-hydration: with oral re-hydration salts (ORS) solution. ORS is a mixture of clean water, salt and sugar. It costs a few cents per treatment. ORS is absorbed in the small intestine and replaces the water and electrolytes lost in the faces.
- Zinc supplements: zinc supplements reduce the duration of a diarrhea episode by 25% and are associated with a 30% reduction in stool volume.
- Rehydration: with intravenous fluids in case of severe dehydration or shock.
- Nutrient-rich foods: the vicious circle of malnutrition and diarrhea can be broken by continuing to give nutrient-rich foods – including breast milk – during an episode, and by giving a nutritious diet – including exclusive breastfeeding for the first six months of life – to children when they are well.
- Consulting a health professional , in particular for management of persistent diarrhea or when there is blood in stool or if there are signs of dehydration. Everything you needed to know about diarrhea disease, how it spreads, and how dangerous it really is too sensitive populations.