Burping continously and getting acid reflux on Distilled water fast, why?

I am 13 days into a distilled water fast, about day 9 I started to burp profusely and get mild acid reflux, The burping has gotten worse since day 9 and the acid reflux comes on intermittently. Symptoms seem to increase when I drink the distilled water. Any Answers? Hypothesis', I don't want to break fast. I'm hoping to go 25-28 days. This is my first extended fast. Tweet