I'm so sorry you got bad results from your colonoscopy.
I can completely relate, because I also had a temporary ileostomy and was told that it could be reversed after 6 months IF my colon healed up.
My colon didn't heal either, so I ended up having a proctocolectomy, which is where they remove the entire colon and rectum. They kept the ileostomy in place, making it permanent.
If, after doing your research, you find out that you would prefer to keep your ileostomy, you could have the same surgery done. If you choose to have a colostomy, it would be permanent, too, since there wouldn't have a rectum to connect to.
I only know about
ileostomies, so I can't answer any of your other questions, but I'm sure someone who has one will be able to.
Hang in there. It's going to be okay.
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again :)