Looks like you've got some solid advice. I'll add in that a shower wand can help clean the area if a bidet isn't working (sitz bath can help calm the burn as well).
When I first had my pouch, any sugary products would cause intense butt burn and liquid stool (I can eat almost anything now). You might try going back to a bland diet for a day. Slowly introduce new foods in case one of them is causing the burn or liquid stools.
Bananas can also help slow things down and provide a nice dose of potassium.
Yogurt, Kefir might help although this soon after getting your J-Pouch, dairy might take some time to process again.