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.
(..) - See, he's swimming away. - Come back. You've offended him. Maybe a different dialect. This is not whale. You're speaking, like, upset stomach. - Maybe l should try humpback. - No, don't try humpback. - You sound sick. - Maybe louder, huh? - Don't do that. (..)2003 Finding Nemo
(..) - Then you were, like, whoa... - What are you talking about? You, mini-man! Taking on the jellies. You got serious thrill issues, dude. Awesome. Oh, my stomach. Man, no hurling on the shell. l just waxed it. - So, Mr Turtle... - Dude, Mr Turtle is my father. Name's Crush. (..)2003 Finding Nemo