Diarrhea is pronounced dy-ə-REE-ə (IPA /ˌdaɪəˈriːə/). Stress 'REE'; four syllables — 'dy-uh-REE-uh'.
IPA: /ˌdaɪəˈriːə/
Syllables: dy · ə · REE · ə
Common ESL mistake: Learners stress 'dy' saying 'DY-arrhea'.
Tip: Stress 'REE'; four syllables — 'dy-uh-REE-uh'.