Toddler Bloated Stomach Toddler Stomach Bloats?

Toddler stomach bloats? - toddler bloated stomach

My baby nephew is about to 2 again in a few months. But the question is when you wake up, your stomach is flat and apparently normal, but if you eat the stomach tends to grow and he has a stomach for the rest of the day. You seem very well on foot and twice a day, eat normally, and a hyperactive child is happy, I'm just curious why the stomach does it work?