Hey - are you constipated? If so its probably the cause of the smell! (Diarreah is also a sign - basically is food staying and rotting inside your body!) I've written about this before if you check my posts, about the kind of simple diets you can go on to increase your fible (carrots good!) - basically you need to get your bowels going properly (at least once a day - optimal 2-3, one for every meal!).
Flaxseeds/linseeds an easy way to get that. You can take them a variety of different ways (makes sure you drink enough water). Sprinkle like 3 tablespoons (whole flaxseeds) over a museli in the morning and eat - take a couple of tablespoons during the day.
The smell should go quite quickly - couple of weeks - once your bowels are regular - you should be okay.