sudden burping.

I am a gibert by birth,jaundice struck me at the age of 16, and now from the past few years i am facing the problem that suddenly i start burping and if i eat something i vomit their and then and everything becomes normal. this is happening from the past 3-4 years,earlier it was happening once or twice in a month but now a days its frequecy has changed to weeks like once in a week.
Please suggest me something for this i had all the check ups regrding nothing comes up.even my weight never went up from 59 kgs,means i m under weight with height 5'11".
I will be waiting for your Reply.