How to Say "upset stomach" in Spanish
The Spanish word for “upset stomach” is “diarrea” — A2 level.

Examples
Tengo una diarrea terrible desde ayer.
I've had terrible diarrhea since yesterday.
El médico dice que la diarrea es un síntoma de una infección.
The doctor says that diarrhea is a symptom of an infection.
Si la diarrea persiste por más de tres días, debes ir al hospital.
If the diarrhea lasts for more than three days, you should go to the hospital.
Gender Rule
Since this word ends in '-a', it is a feminine naming word. You should always use 'la' or 'una' with it (e.g., 'la diarrea').
Using it with Verbs
Just like in English, we use the word for 'to have' (tener) to say someone is sick with this condition.
The One-R Trap
Mistake: “diarea”
Correction: diarrea. In Spanish, when an 'r' sound is strong and vibrates between two vowels, you must use two 'r's.
Related Translations
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