If you've just had a really big meal, there are a lot of things going on in your body. Between the stomach stretching and the chemical reactions taking place, here's an explanation of what's going on in there.
This video from the America Chemical Society's YouTube channel, Reactions, breaks down everything you ever wanted to know. For example: your stomach stretches out to the size of a large burrito, you start purging copious amounts of different gases, and there's a specific chemical that tells your brain to put down your fork. So before you fall asleep from being too full, give this video a watch.
What Happens When You Eat Too Much [YouTube]