I struggled for two years after takedown with this problem. Was seriously considering giving it away if I couldn’t have a comfortable life. I found that flagyl or cipro stopped the burn and made me feel normal (reduced the number of motions too). What I discovered was that after a course of antibiotics I would get between 1-3 weeks where I could do without them before the pouch became unsettled again ( and the burn returned intermittently). So I have stuck to a regimen of rotating antibiotics- 10 days cipro, as long as you can without any, then 10 days Flagyl. Been doing this for 4 years and tolerating it well. Not ideal to be on antibiotics a lot of the time but better than being in pain. Maybe give this a try.