Your BM's will gradually get lower and lower. Your body is still adjusting to the new setup.
Immodium is your friend right now.
Ohh, and if you don't have Calmoseptine yet, you might want to get some. Butt burn and butt itch, if you haven't experienced them yet, are coming. . .and then it passes.
I found a bidet was a HUGE help in keeping my butt clean without using TP (TP chaffed something awful!). That stream of water also helped with butt itch.
Congrats on your J-Pouch!!! Honest, you're gonna adjust and never think about it again.