I remember reading an English translation of The Story Of O in which the word “belly” was used as a euphemism for vagina. It was…terribly confusing.
Also when I read the original question, the first thing that came to mind was the Ramona book where she gets upset and announces to her parents and older sister that she’s going to say a bad word. She then yells something to the effect of “GUTS GUTS GUTS” at the top of her lungs and is rather annoyed when she realizes everyone is trying to not laugh at her.
I read alot of stuff.