machine gun turd
you’re pooping and you let out a few farts so fast they sound like a machine gun, just to be extra smelly
I was crapping and I let out three farts in a row like a machine gun. The smell was unbearable.
He was taking a dump and let out a whole bunch of farts that sounded like a machine gun. It was disgusting.
She was going number two and let out a few farts that sounded like a machine gun. It was a stink bomb.