I had the same problem but now I find my, doctor prescribed, 10mgs daily Omeprazole does the trick admirably.
I am a few pounds overweight, according to the online charts, so I watch this by mainly sensible eating and exercise.
My personal theory is that, because the top third of me has settled more closely down upon the lower two thirds, my stomach is squashed upwards, thereby causing acid to come up more easily. My doctor laughed when I told her that. (They don't know everything obviously
)