What WHO means by diarrhoea
WHO defines diarrhoea as the passage of three or more loose or liquid stools per day, or stools that are more frequent than is normal for the individual. WHO also notes that frequent formed stools are not diarrhoea and that loose, pasty stools in breastfed babies are not, by themselves, diarrhoea.
Why dehydration matters
WHO describes dehydration as the most severe threat posed by diarrhoea. Water and electrolytes are lost during a diarrhoeal episode, and dehydration develops when those losses are not replaced.
How WHO classifies dehydration
WHO’s diarrhoeal-disease information describes severe dehydration using combinations of clinical signs including lethargy or unconsciousness, sunken eyes, inability to drink or drinking poorly, and a skin pinch that returns very slowly. It describes some dehydration using combinations that include restlessness or irritability, sunken eyes, and drinking eagerly or being thirsty.
Oral rehydration information
WHO explains that oral rehydration salts (ORS) replace water and electrolytes lost in stool. WHO’s 2024 guideline recommends low-osmolarity ORS in children up to 10 years of age with acute watery diarrhoea and dehydration.
Food, hygiene and prevention
WHO identifies continued nutrient-rich foods, including breast milk, as part of diarrhoea care. Its prevention information includes safe drinking-water, improved sanitation, hand washing with soap, good personal and food hygiene, exclusive breastfeeding for the first six months of life, and rotavirus vaccination.
When WHO identifies professional assessment
WHO specifically identifies professional consultation in connection with persistent diarrhoea, blood in the stool, or signs of dehydration. For any concern relating to an individual child, consult a qualified doctor.
References
- World Health Organization. Diarrhoeal disease.
- World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age, 31 December 2024.