You'd be surprised what people can put up with cheerfully. A relative of mine turned out, around high school or so, to be allergic to wheat (which is in half the stuff you eat). It gave him regular diarrhea. He had grown up with it and simply assumed it was normal. How would he know otherwise? (A version of the 'typical mind fallacy' https://www.lesswrong.com/posts/baTWMegR42PAsH9qJ/generalizi... one might say.)

It's not as if people go around saying, 'good morning! I had my usual poop today, a good #3 on the Bristol stool scale, placing me within 1SD of the human norm! And yourself?' 'Likewise, likewise; good checking in with you and discussing our morning defecation, as is very normal for us human beings, ha ha.'

Start an elimination diet. Chicken and green vegetables are a good starting point. I did chicken and sweet potatoes for a month. Had a ton of issues go away.

Turned out practically everything bothers me.

AIP diet has been a life changer.

Go to an allergist. You may end up getting referred to a GI. But it's a sure-fire way to know if you have actual allergies or not.

Source: Wife's visit to allergist & subsequent referral to GI doc today (no allergies).