Take this medication 'on an empty stomach'. [=when your stomach is empty because you have not eaten for a time]
When I had the flu, just the thought of eating made me 'sick to my stomach'. [='nauseous']
She felt a flutter in 'the pit of her stomach' when he walked through the door.
(..) mechanic that walks around here. Big guy, a liar, short name. Sam, Mo, Sol-- George, can we focus on the car here? I'm starving. I can feel my stomach sucking up against my spine. Well, I need your signature here... ...and we'll get you that yellow car ready to go. Yellow? I wanted black. (..)1998 TvShow: Seinfeld Title: The Dealership Season: 9 Episode 11