About three or four times a month I wake up during the night with severe burning in the center of my throat. This causes me to have involuntary coughing fits which in turn cause me to vomit. I assumed I was brining up bile, but noticed it is quite viscus. I also bring up phlem. Two years ago I had hiatal hernia surgery. It was a very large hernia. The throat burn began several months after the surgery. They may or may not be connected. I've had two Endoscopies, both were clear. I take Omeprazole twice daily, but it doesn't stop the problem. I don't know what to do and could use some input.