Busting a gut

[Bushwhacker]

Talking on Superheroes, like Fantastic Four, what can be understood for "Busting a gut"? Something like beating a stomach?

It seems some special superhero's gift

Thank You

[Graver]

It may have two meanings.
Just take a look:


http://idioms.thefreedictionary.com/bust+a+gut

It is based on the idea that extremely hard physical work or laughter could damage your gut (= stomach)

Graver

[susiedqq]

He busted his gut building that house. (He worked very hard to build his home)

He was busting a gut watching cartoons. (He was laughing so hard that his stomach hurt)

[Ouisch]

Usually in AmE "busting a gut" means laughing heartily or uproariously.

"I nearly busted a gut when I saw Fred slip on that banana peel and fall down."