As in Portuguese sometimes we use the word "stomach" meaning "estômago" and other times to mean "barriga". There´s some intersection in meaning, so sometimes they can be interchangeable. It goes with context.
For instance, it could be "barriga":
My stomach hurts.
My stomach is bloated.
I was already having butterflies in my stomach.
Take 1 capsule per day on an empty stomach, preferably two hours after the evening meal. (here - barriga OR estômago).
After an alcoholic drink is consumed, the alcohol is absorbed rapidly from the stomach and intestine into the bloodstream. (estômago).
By then I already felt sick, nauseated, with pain in my stomach and diarrhea. (could be translated into "estômago" or "barriga".)
It's just that my stomach isn't bothering me anymore.
Here certainly "estômago":
For five years during the time I had my stomach problem, yeah.
My lips felt cold and stiff, and my stomach hurt.
Here "estômago" or "abdomem":
Any tummy tuck surgery evaluation must be done after this period.
Abdominoplasty, also known as tummy tuck or abdominal dermolipectomy, seeks to enhance the waist and the lines in the region by removing the excess skin and creating an abdominal firmness.