I had a hiatal hernia repaired during my sleeve surgery too. I had no idea that it was there, but my doctor said that it was really large. Looking back, I guess I could have noticed some of the signs, but maybe I had been living with it too long.
I left the hospital with a prescription for omeprazole, (Prilosec) and I've felt okay. Maybe it wouldn't be too bad of an idea to just have him give it to you to see how you do with it.