Very few members here have an ileorectal anastomosis. The vast majority have an ileoanal. That said, the ileal j-pouch performs similarly to a rectum. With a rectum, you should have less problems emptying, not more, since the rectum has muscles that the ileum doesn't.
Anyway, some of us do have emtying problems and nightly enemas or drainage by tube can work.
As mentioned before, stepping up your fliuds may help. Fiber supplements may also help you empty by adding more bulk to your stools.
Jan 