I had a loop ileo initially but had to have it turned into an end ileo 6 months later as the loop pulled back on itself and so everything was flowing through as if the ileo didn't exist. They left my colon in place until I had that removed 7 years later and during that time I also had small amounts of bowel motions and mucus.
Gradually it got worse until I was having to go so often that it was just like it was before the ileo even though it was only very small amounts the urgency was terrible. I never regretted having the ileo and was only 20 y.o when I had it done as it gave me my life back as my Crohn's was a agressive form and didn't want to settle down.
I still have flares of the Crohn's and am on immunosuppresants for life and that keeps in it check. Having a bag is a personal experience and not everyone likes it and you are obviously desperate to have it reversed so hope this works out for you. Just remember that if at some point it has to be done again, it isn't the end of the world. In fact it can be that start of living a normal life with no running to the bathroom and no pain. Good luck with your reversal and hope you CD stays in remission.