brew

The brew is the contents of your stomach after eating an absurd combo of food. Much like the contents of a witch's cauldron is a crazy mixture of things. The brew is usually apparent with stomach cramps and growls.

Friend 1: "Get me to the bathroom! My stomach is cooking up a nefarious brew right now"
Friend 2: "Maybe you shouldn't have eaten an ice cream sundae right after Taco Bell"