I can push my stomach out and in and make gurgling noises, is this normal?

When my stomach is empty, or when it only has like, liquids in it, I can push my stomach out (like i'm trying to look pregnant), and then back in and it makes really loud noises everytime. Is this normal? Its the only stomach problem I have, except I'm getting a colonoscopy tomorrow to see if i have crohns disease, but have you ever heard of this before?