My father is visiting this weekend. The female personalities are at the fore again, and they are pursuing their long-held dream of gender reassignment. It hurts the feelings of the ladies that I can't whole-heartedly endorse their goal. For people who don't know, or don't believe, in DID, it's easy for them to congratulate my dad on pursuing this. My husband, for instance, thought it seemed fine, and didn't really understand why I objected. Sorry. As cool and PC as it would be to have a transgender GP ("Genetic Parent"), I have my doubts about the wisdom or fairness of someone with DID getting permanent gender reassignment surgery.
The fairness issue really bothers me, in particular. If multiple personalities aren't in any real sense "different" personalities, then all that is at issue is self-delusion. But if a multiple really does create the equivalent of unique sentient selves, who happen to share a single body, then, for one or a handful of the personalities to gang up against the others and impose a decision they don't all agree to, is no different than any other form of bullying. Either way, we're not talking about a viable long-term solution.
As a science fiction author, I can think of much better solutions. In my Xenophile series, people use cellular-regrowth technology to disassemble their bodies and rebuild them cell by cell, leaving only their brains untouched. They use this to take on alien forms and infiltrate alien societies. I hypothesize that only certain humans have flexible enough minds to deal with this transformation, and most people don't do it. But ordinary people also use a more modest version of the tech for cosmetic changes to their bodies -- sculpting the look they want, rejuvenation, costumes for fancy parties, and gender switching.
If we really had such tech, it is obvious how someone with DID would use it. The inner vision of how the different personalities could become the external reality of the physical body. This might seem to expose to the world that the individual was a multiple, but, in fact, in such a society, singletons would also switch bodies frequently enough that I doubt one would be able to assume DID just because one had a number of "looks." It would be like the internet, where hardly anyone can resist the temptation to create multiple anonymous and pseudonymous identities.
Anyway, that way the girls could have the body they want and the boys could have the body they want. Everyone would be happy.
Well, probably not happy. Because the same brain would be present, no matter what the shape or gender of the body, and I believe the brain is the source of more problems than the body.
That's another matter.