Again, everyone is different. I have no problem holding a BM but when I'm asleep, doing something physical (straining etc) it can be difficult. It's all about finding what works for you. I'm still changing and adjusting everything. I would always suggest trying a jpouch as long as your doctors are for it, you can always go back to a bag. I had major irritation by the time my jpouch was ready, my stoma site didn't want to heal together nicely.
Good luck