expression
if you don't speak your mind, you'll feel uneasy afterwards
Proverb warning that bottling up your thoughts leads to inner discomfort, like a bloated stomach. The phrasing is classical and not used in everyday speech.
「思う事言わねば腹膨る」という諺がある。
There is a proverb that says, 'If you don't speak your mind, you'll feel uneasy afterwards.'
This proverb advises silence to avoid trouble, while 思う事言わねば腹膨る encourages speaking up to avoid inner turmoil.
A classical Japanese proverb. The exact origin is uncertain, but it reflects the folk belief that unspoken thoughts cause physical discomfort.