I believe your stomache is emptied of a fairly decent "meal" (whatever that is) in roughly 1 and a quarter to two hours, depending on your state of health.
Should (we) look it up. I've read it a zillion times. I have the opposite problem. ; )
But you'd be surprised how quickly the stomach empties. And depending on what you eat/drink. It's good to keep in mind because unless you are obese, the actual stomach itself should process things onward relatively fast.