acid attacks
After 2.5 years out I still dump occasionally and I can tell you it's nothing like you're experiencing, and I haven't had one incident of acid reflux since my WLS either, so I will back up what the others are saying and call Barix ASAP, explain to them what is going on and ask to see Dr P sooner than the 28th.
Could it be too much coffee or tea ? I was hooked on McD's iced coffee sf of course and OMG after a bit of time my body said whoa hold off on that coffee and had to switch to water and 1% milk and such so it could be that or have you started taking any new meds? I can remember after addressing my heart issues after having three stents put in I was prescribed something which caused me to have a horrible cough and when I touched base with my cardio he said yep it was a side effect well duh what the hell switch me to something else! So I see three possibilities or you could be eatting too late or something too heavy or spicy? Good luck with trying to find out what it is and hope you feel better.