I am a flight attendant with a j pouch. Have had it working since take down in October 09. I was off work for 6 months from my colectomy surgery.
I am doing fine and sometimes can get thru my duty day without having to use the lav at all. I usually try to work earlier in the day, if possible.
I think you will do fine. Just make sure you can take enough time off initially when your pouch is new.