Pancia vs. ventre
While 'pancia' and 'ventre' both refer to the belly or abdomen in Italian, they have subtle differences in usage and connotation.
Pancia
'Pancia' is the more common, everyday term for belly. It often refers to the external appearance of the abdomen and is used in casual contexts.
Ho la pancia piena.
(My belly is full.)
Sta mettendo su pancia.
(He's putting on a belly.)
Mi fa male la pancia.
(My stomach hurts.)
Ventre
'Ventre' is a more formal or medical term. It typically refers to the abdominal cavity or internal organs, and is often used in scientific or literary contexts.
Il chirurgo ha esaminato il ventre del paziente.
(The surgeon examined the patient's abdomen.)
Il ventre della balena.
(The belly of the whale.)
Soffre di dolori al basso ventre.
(He suffers from lower abdominal pain.)
Summary
While 'pancia' is used more casually to describe the external belly, 'ventre' is often employed in more formal or anatomical contexts. 'Pancia' might be used to discuss weight gain or a stomachache, while 'ventre' would be more appropriate in medical discussions or poetic descriptions.