I'm sorry you have to go in for another surgery, but if you have active Crohn's, it's best to get rid of the parts that are diseased. I felt so much better after my proctocolectomy in 2006 and have been Crohn's free ever since.
I had my ileostomy for 8 months before having a proctocolectomy and actually had a harder recovery with the ileostomy than the other, because my ileo took 10 days to work. With the proctocolectomy, I was out of the hospital in 4 days and was driving and grocery shopping after 2 weeks. I was so surprised, because I was expecting the recovery to be much worse.
Since your ileostomy is already in place and working, you are not going to have to wait for it to work, which can take up to 2 weeks with a nasty NG tube in place and no food or water.
Hang in there, it's going to be okay! (((big hug)))
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again.