What does diarrhea mean?
Diarrhea refers to the condition of having abnormally frequent, loose, or watery bowel movements, typically occurring when the digestive system passes food through the intestines too quickly for water to be properly absorbed. It is one of the most common digestive complaints worldwide and may result from infections, food poisoning, medications, stress, or underlying conditions such as irritable bowel syndrome. While usually mild and short-lived, persistent or severe diarrhea can lead to dangerous dehydration, particularly in young children and older adults, making it a major focus of global public health efforts. The word functions as an uncountable noun in standard English and carries a clinical register, though it appears freely in everyday conversation about illness. In British English it is spelled 'diarrhoea', while American English prefers 'diarrhea'. Derived adjectives such as 'diarrheal' appear frequently in medical writing. Its Greek etymology — literally 'flowing through' — vividly captures the condition it names, making the term both precise and historically transparent.
nounA condition in which the bowels are emptied too frequently and in a liquid form; abnormally frequent, loose, or watery stools.
- Frequent discharge of loose or liquid feces; a common symptom of intestinal infection, food intolerance, or other digestive disorders.
"The travelers were warned to drink only bottled water to avoid diarrhea."
"Antibiotics can sometimes cause diarrhea by disrupting the gut's natural bacteria."
"The clinic treated dozens of children suffering from severe dehydration caused by diarrhea."
Diarrhea has no plural form in standard English; it is used only as an uncountable mass noun. Episodes are referred to as 'bouts', 'attacks', or 'cases' of diarrhea.
"He suffered several bouts of diarrhea during his trip abroad."
The word 'diarrhea' comes from Greek roots meaning 'to flow through' — the ancient Greeks described it exactly as it sounds.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diarrhea
Diarrhea derives from the Greek 'diarrhoia', formed from 'dia-' meaning 'through' or 'apart' and 'rhein' meaning 'to flow', so literally 'a flowing through'. The term passed into Latin and then entered English in the early modern period, with the spelling 'diarrhoea' reflecting its French intermediary 'diarrhée'. It shares the Greek root 'rhein' (to flow) with words like 'diuretic' and 'rhythm'-related terms via related Indo-European roots. The simplified American spelling 'diarrhea' became standard in the United States through nineteenth-century spelling reforms.
Related word forms
How diarrhea is actually used
Standard medical and everyday term in American English, spelled 'diarrhoea' in British English. It is considered somewhat clinical or blunt; in casual speech euphemisms like 'an upset stomach' are often preferred. The adjective forms are 'diarrheal' (US) and 'diarrhoeal' (UK).
Easily confused with diarrhea
Diuresis is excessive production of urine by the kidneys, whereas diarrhea is frequent watery bowel movements.