I'll keep this short for now but may elaborate later:

I found this site years ago and based on the descriptions of other participants, judged myself to be among the worst cases as far as shy bowel goes. Since age 19 I insisted on living alone to accommodate the problem. I went from avoiding trips to spending money on cheap motel rooms to which I could escape on trips with others (which I continue to do), but worst of all, I was never able to share a living space with a significant other. What's worse, I remained pessimistic about my future in this regard.
Finally, over ten years later, I've discovered that I can comfortably have bowel movements with a girlfriend in the same residence. Granted, the bathroom needs to be removed from whatever room she's in, but I was SHOCKED to discover this was possible. It means I can share a house someday with a woman, and have a family under the same roof. I used to maintain the last resort plan of having TWO residences (one small place in which to poop privately, in addition to my main domicile) to make family life work, but now I know this is not necessary. Whew! Life just got much more affordable.
I am by no means cured, nor has the problem ceased to impact other aspects of my life, but the point is that it is possible to make great progress. I was as doubtful as anyone that I would ever improve. What helped me was being comfortable enough to discuss it with an intimate partner who was willing to talk openly about it without judgment. Perhaps more importantly, I finally CARED enough to face my fears and TRY going while having my partner in another part of the house. In fact, they were on another floor of the house to begin with. Due to subsequent moves, I was put in successively less private situations with her. Currently I am pooping on the other side of one wall from my partner's location during the mornings, and doing admirably.

My message to others on here who may have suffered (or are suffering) like I have for so many years --- progress is possible if you are willing to tolerate setbacks and experience being out of your comfort zone.

Happy to describe in greater detail if anyone has questions.

Thanks for keeping the site running, Baz!