We discussed this a while back. Last fall someone suggested that the
cause might be too LOW stomach acid, so that the esophagus didn't get
the message to close properly. I poo-pooed that at the time, because
acid foods clearly made it worse for me. But I was wrong.

Experimenting around, trying lots of different things to see what the
effect might be, I drank some pickle juice. Vinegar, water, salt and
honey. Hmm. No pain. Tried it again the next day. Good. So I kept
trying it every time I felt  a burn, and every time, within a minute or
two, the pain disappeared.

Been about two weeks now. I take one drink of a little vinegar/water if
I feel any pain. No trouble and I feel loads better physically.

But other acid foods like oranges still cause the burn. Strange, maybe
the acetic acid in vinegar passes a chemical signal that citric acid
doesn't? I don't know. I don't see how drinking vinegar is paleo ;--)
but I would be interested to know if anyone else with heartburn has
tried this, and how it worked.

I take one drink, about one part vinegar to three parts water, then a
sip of water to chase it down.