Understanding Excessive and Odorous Belching: Causes & Solutions

Question
My roommate has started belching A LOT and not only is the sound annoying (sounds forced) but afterwards the room smells like the belch came from the other end (if you know what I mean).  What could possibly be causing this?

Answer
This may be simply a combination of what your roomate eats and the time it has been rotting in their stomach, esp if forced, but,

it also suggests infections like giardia, dental disease or a food intolerance (like milk)   

If the belching is simply forced, the novelty is over.... if it is a true symptom, it is worth your roomate getting it looked at.....