So, what happens when you eat Styrofoam? Well, it's not like your body is going to absorb it or anything. Instead, it'll just kind of... hang out... in your stomach and intestines, causing all sorts of trouble. It's like having a foreign object inside you, refusing to budge.
What Happens If You Eat A Styrofoam Cup at Kathleen States blog
It's also worth noting that Styrofoam can be toxic if it's ingested in large amounts. It's like eating a poisonous plant or a hazardous chemical - not good, not good at all. And, just like how you wouldn't feed your pet a plastic toy, you shouldn't feed yourself Styrofoam either.
