stomach
The word 'stomaco' is the Italian translation for 'stomach'. It is used to refer to the organ in the body where digestion begins. It is also used metaphorically to express strong feelings, such as 'I have butterflies in my stomach'.
I have a stomach ache after eating too much.
This sentence is used when you've eaten excessively and subsequently you are having a stomach ache. The phrase 'mal di stomaco' directly translates to 'stomach ache'.
Food is digested in the stomach.
This sentence is a typical example of explaining digestion process. It expresses that the digestion of food happens in the stomach.
Full stomach, happy heart.
This phrase is an equivalent of the English saying 'A full belly makes a happy heart.' It conveys the idea that when our physiological needs, like hunger, are satisfied, we tend to be happier.