Heavyness on the left side of chest.

Sometimes I start feeling certain kind of heaviness on the left side of the chest , that lead me to continuous burping , and when I do that certain kind of effect is felt or air is released from there I got this problem 11 months earlier and got it checked by doctor , she checked my bp and have done ECG , after checking the report of it , she told me that it's just an gas problem , nothing else , and given me some medicine and a gel type liquid , for 7 days , and when I took that , I was cured but now I just forgot that medical prescription , so can you plz suggest me effective medicine or that gel kind of syrup/ liquid that can get this problem cured . Please suggest me this as earliest as possible