OMG...I have had the same thing lately. I have been suffering with reflux for years but lately I get that pain in the middle of the back. I have to bang my back against a door frame until I burp and that relieves it to some extent. I take Tums and it also helps a bit. It feels to me like when I was a kid and a Corn Flake got stuck in my esophagus. It is very painful. It reminds me to go to bed with an empty stomach and to lie only on my left side. If need be: propped up as much as I can. Diet time! And avoiding spicy foods, tomatoes, juices, soft drinks, bread and sweet foods which bring on the pain.