your stomach is an organ with layers of tissue and muscles. You can't damage it by vomiting unless you've been an alcoholic for about a hundred years. It's made to stretch and expand, and you have nothing to worry about. check out its anatomy and notice how hard it would be to stretch it or make it pop a staple. even as a small pouch, it still contains its layers. It's several millimeters thick but you can look it up to see exactly how thick that is.
but even if it weren't thick, remember that vomiting originates in the stomach. it's the stomach itself that's sending the food back up as vomit. it just sits there and your vomit response does the rest.
I want to repeat this because as fatties, we're all afraid of stretching our stomachs. but they aren't changed that easily. Just as you can't really shrink your stomach unless you're starving to death and starvation is VERY advanced, you cannot stretch it. Before your stomach could ever be dangerously stretched or affected, it would pass any excess matter into the duodenum and down the small intestine.
So, vomit away! Your stomach is the boss here, not you. Have no fear!
