Geeez! Well, I have noticed that when I eat anything my stomach isn't used to digesting, it saves the gas from that wonderful experience and lets me "have it" at the worst possible time. Perhaps, if you are old enough, you'll remember college drinking days. How awful it was to be having "gin" burps at three o'clock the next day.
My husband only has "questional, or borderline" foods for lunch, that way he can take a walk, and generally be upright for several hours, and even have another meal on top of the "boo-boo" food. We have pretty favorable food for lunch, and go back to the bland stuff for dinner. He says dinner seems to be able to "lay" in his stomach for hours.
The good news is, gas goes upward. Just like a little baby who needs to be burped after having their bottle. This burping process cab take awhile, holding the child upright, walking with them and patting their back. By the way, babies can also have GERD, bummer right? All that patting and walking will eventually make the child burp, a great big, sour-milk burp.
I have no idea how far down the intestine gas goes, well, it can actually "go" all the way, if nearest the throat you get a burp, if nearest to the other end, you get a fart. I don't mean to be gross, but people with a disgestion issue often have pass gas that is warm, and smells very much like what they ate. So, I don't think what you are experiencing is is way off the mark, but it is probably something your stomach has trouble doing with ease what is usually done.
My husband does continue to eat certain questionable things because he does not want his digestive track to forget how to digest it. Any time he stops eating or drinking something and then tries to go back to it after several months, it gives him big problems. He has stopped drinking caffiene for a while and then started again, all this stopping and starting has made him ultra-sensitive to caffiene now.
I always believe you should see your doctor to make sure it isn't something bad, after that, sensible portions, and eating 80% stuff that's good for you, and only eating 20% stuff that is Taking a Walk on the Wild side.
Good Luck, Gremma