Shouting Groceries

The euphamism "Shouting Groceries" means vomitting. This phrase came up because when your throwing up your mouth opens wide open as if you were shouting and it makes loud vomit noises. The groceries part is because groceries is food and when your throwing up your letting out all the food you've eaten. Therefore your shouting out groceries, and its just another way to say vomitting or "throwing up".