Once you can identify the most likely cause in your case then it is a matter of avoiding the trigger factors. If you have any GI disorder, then you may need to see a doctor who can prescribe the appropriate treatment. This will help your symptoms like belching and bloating to resolve.
matt
It depends on what is causing the bloating and belching. You can read this article on excessive gas in the upper gut. http://www.healthhype.com/excessive-gas-in-the-upper-gut-stomach-intestinal-causes.html
Once you can identify the most likely cause in your case then it is a matter of avoiding the trigger factors. If you have any GI disorder, then you may need to see a doctor who can prescribe the appropriate treatment. This will help your symptoms like belching and bloating to resolve.