Hi Mema
I have no idea if this will help you because it sounds too good to be true but FWIW I have experienced a remarkable turnaround in my J-Pouch health after starting a daily routine of eating one cup of cooked Steel-Cut, Gluten Free Oatmeal every morning. (Nothing else in my diet has changed, although I do avoid gluten, and try to limit dairy and sugar)
In addition to the benefits of the fiber, my theory is that the unprocessed oat absorbs some of the acid that used to make my life miserable and more importantly acts as a "broom" to sweep out everything I ate in the preceding 24 hours. After eating the oatmeal (every morning without fail) I am able to be out and about...pretty much without any urgency... through mid afternoon. At that point, I'm usually home and after a couple of trips to the restroom, (late day/early evening and before bed) I'm in good shape for the night.
If you do have fissures or pouchitis, you'll probably have to get those problems resolved first and I don't know if this suggestion will help or hurt on that score. I do know how painful what you're describing is and hope that a tip from someone on this site or script from your medical provider will help you resolve this issue soon. Good luck .