1) Could be underproduction of stomach acid. Try Betaine HCL (with pepsin) and titrate upwards until you find your "safe" spot. SCD Lifestyle probably has the best
guide I've come across in my internet travels.
2) I had terrible reflux issues after antibiotics, but eating a small serving of fermented foods with meals (sauerkraut, kimchi, pickles, etc) fixed it right up, so that could be another option for you. Yogurt, kefir, raw milk helped fix some underlying issues as well.
I think the second option works the best, but everyone is different and you have to experiment a bit.
Hope this helps!