Food regurgitated after eating

For about an hour after I've eaten anything, every few minutes or so, what I've eaten is involuntarily but painlessly regurgitated back into my mouth. It does not taste bitter. It tastes like whatever I was eating. I either chew and re-swallow or dispose of this regurgitated food.

I have no other symptoms at all. I am under no stress and follow a healthy diet. I used omeprazole, but to no avail.

What is this? Please try to help with a concise and expeditious answer. If you have any questions, please ask them. Thank you.