Yep.ive had that. I actually went through ALL the tests too.if u look at my past posts(if there's a way to)you'll see me asking a very similar question. I am doing ok now,it took several months to go away. Its called esophagitis. Nothing to worry too much about,check with ur dr of course:-) but ya i completely lost my mind when it was happening and trying to describe it to people is hard. The pain in your back is a referred pain from your esophagus.its like hitting a nerve sorta.