ENGLISH
REFERENCE

diarrhea

n.
US //ˌdaɪɝˈiə// di·ar·rhea
  1. 1 the illness (n.)
    B1 Intermediate American English Medicine

    an illness that makes you go to the toilet more often than usual with watery waste.

    a medical condition or symptom involving frequent and liquid bowel movements. Uncountable in general reference, though countable when referring to specific instances or types.

    Example

    He stayed home from work because he had bad diarrhea and a fever.

    Example

    The doctor explained that severe diarrhea can lead to dangerous dehydration if the patient does not replenish fluids and electrolytes.

    Usage

    Usually used without an article when referring to the condition.

    Teacher's tip

    This is the American spelling; the British spelling is 'diarrhoea'. Both are pronounced the same way.
    • loose stools
    Pitfall
    I have a diarrhea.
    I have diarrhea.

    When talking about the illness in general, do not use 'a' because it is usually uncountable.

Origin

From Middle English diaria, from Middle French diarrie (French diarrhée), from Late Latin diarrhoea, from Ancient Greek διάρροια (diárrhoia, “through-flowing”), from διά (diá, “through”) + ῥέω (rhéō, “flow”). By surface analysis, dia- + -rrhea. Spelling later altered to resemble the word's Latin and Greek roots. Displaced native Old English ūtsiht (literally “straining out”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Last updated June 20, 2026