Hollow feeling in pit of stomach

Sorry have been a way for a while. Family in town for a month and we have been really busy. Will get back to posting soon.

I noticed last week one time and tonight after I ate I had this hollow feeling in the pit of my stomach. This is a strange feeling. And I am not familiar with it but I recall people had mentioned it years ago.
It is not a good feeling. I am going to try to drink a glass of water and see if that helps. Has anyone else had this happen. The only change in my routine is I am back at the gym (water fitness classes).

Kari