Hello BrooklynBlast. It is indeed an interesting question, which I believe will ultimately be answered by gay people themselves.
I feel sure that there will be many 'straight' people who simply do not want to think about this subject, let alone talk about it. Nonetheless, the question has been raised so, although admittedly 'straight' myself, I feel I should have a go at giving a considered hypothetical answer.
From my perspective I would want to know if we are talking about anal sex or sex with the stoma. If a person is left with enough of an anal stump, then, after the healing has taken place, I cannot see any physical reason why the act of anal sex should not take place. If however, we are talking about sex using the stoma, then many complications may arise. The stoma is formed by stitching the colon to the outside skin. This inevitably forms scar tissue which is somewhat inflexible. Thus, anything larger than a finger ( or stools) that is pushed through/into the stoma is likely split the rim.
Having said that, I insert my finger in my stoma every day to see where my peristomal hernia has migrated to so that I can insert an irrigation tube. After irrigation I insert a stoma plug. There is therefore, something in my stoma continuously during the day.
Years ago, when I had problems with my anus (scar tissue closed it up completely after surgery), they gave me a dilator to use each day, which helped to keep the hole open and to expand it slightly so that the faeces could exit. I now use a dilator to keep my hernia from closing over the hole inside the stoma and it does work to a limited degree. I would not recommend this method to enlarge the hole anymore than is necessary to have output.
Also, it is probably something that should be discussed with medical staff. My motivation for doing this was the thought that if something went wrong, I might perhaps find myself having to explain 'why' it went wrong at sometime in the future, if and when I might need their help to put it right.
In summary: I feel it is very unwise to contemplate sex using the stoma. Anal sex is probably still possible, depending on how much colon has been left to form the anal stump.
I feel sorry that you have felt the need to ask this question as it is something very personal which normally does not get discussed in an open forum. There are sometimes occasions when we feel the loss of something that we once had but now have no longer. We know that the mourning process can sometimes be helped by sharing and discussing our feelings with others (who are willing to listen empathtically). I hope that by joining in this discussion you can feel that there iare people who are willing to listen to your situation and contribute constructively to the contemplative process.
Best wishes
Bill