Well, I can give you my opinion...You are just expereincing the tip of the iceberg!!!

The foul burp is probably due to food sitting in the stomach for too long.

It usually happens to healthy eaters!

That is because healthy food is so packed with nutrients that it takes a long time for the tummy to break it all down!

Some foods are worse then others.

Fatty foods are the worst, simply becasue fat can take hours to break down. If you have something soon after eating fatty foods, you may have a foul burp, becasue fat floats as well so it will go on top of what you already have eaten and by that time it has fermented and is really yucky and comes out foul! In my expereince the worst fatty foods are nut butters! Becasue they combine protein and fat, which is the a really bad combination! Fish seems to be fine for reasons too long to go into here. Meats are OK but may give problems. Eggs are terrible. Because they have sulfur in them as well as fats and proteins.

Which brings me next to sulfur containing foods (but not meats usually for reasons too complciated). So, garlic, onion, broccoli, leeks and so forth and so on.

And then there is too much protein. Too much protein takes too long to break down and ferments, and you are buggered as well.

So, you may find food combining helps (plenty of websites on that).

You may find not eating fatty foods helps.

You find not overeating helps.

You may find waiting at least 4-5 hours before your next meal helps.

Simple carbs are easy to digest. You will find they rarely give problems and if they do, it is usually something else bad you eat.

And whatever you do, do NOT eat fruit!!! Except on an empty stomach and only on an empty stomach, and do not eat it every day or you will be buggered!!!

All these help the stomach process foods quicker and reduce the risk of fermentation.

Thats what I think anyway... :)