Gas problems, halitosis, and other issues

For a very long time I have experienced occasional stomach cramps, gas, and frequent throat gurgling. However I thought nothing of it, until I had to be rushed to the emergency room after being diagnosed with a perforated ulcer. My parents, siblings, even the doctors, were absolutely baffled at what could have caused this seeing as I was only 15 and in good health. I still don't know what caused it to this day, even with the many visits to doctors and specialists. I always thought the culprit was H. pylori, but after going through a recent endoscopy which actually uncovered some inflamation (inflammation) in my intestines, the doctors concluded that it was not present.

I'm also starting to think that my recurring halitosis could somehow be linked to all this. I read somewhere that h. pylori could also be present in the mouth. Could it be present in the mouth and not the stomach?

I still have some gas problems today, and after seeing how some people on this website were doing the same solutions for throat gurgling I had made for myself years ago (lying on my back or side), I'm asking for all of your opinions.

Long read, but thanks for your time!