My ileostomy started out as a temporary one, too, just in case I didn't like it. Well, it turned out that I loved it, so, 8 months later, I started bleeding from the rectum (since the Crohn's disease was still active). That's when I had my colon and rectum removed and kept the ileo the same. For me, keeping the colon and rectum in was causing problems, since they were diseased with Crohn's, so it was best to have them removed.
From what I understand, if you're feeling good and are not having any problems, you can keep your colon and rectum in and keep that same ileostomy. You would only have surgery to remove your colon and rectum if they were causing problems and making you sick. Hope that helps explain things a bit.
Dx'd Crohn's in '99 at age 28. Proctocolectomy and permanent ileostomy in '06.
Disease-free and medicine-free since surgery and very thankful to be healthy again.