noun
tummy
TUM-ee/ˈtʌmi/
An informal word for the stomach or belly.
The child rests both hands on her tummy after the meal.
Etymology
Tummy arose as a child's version of stomach, which already referred both to the digestive organ and to the belly. Its child-speech origin explains its familiar, informal tone.
In context
although vomiting feels as if it's due to our troubling tummy however it is triggered by a part of our brain