Hello and
Sorry to hear you are having trouble! I have the same dilemma. The last time I took Miralax, my fissure burned like hell! I though I was going to pass out even sitting in the tub.
I actually just had a fissurectomy (tag removal) and LIS today after 10 days of excruciating pain where over the weekend I had to lay on my belly or walk around slowly or sit in the bathtub. And this is after taking painkillers on top of Aleve or Motrin. It was living HELL! Thank God for this forum!
Right now I have no pain 6 hours post op. It's a miracle!
So anyway, I would also like to know why the fiber products burn so much and if it will burn post op as well. Thanks for bringing up the topic!
One thing that I know helped me was Rectiv (prescription). If your fissure is not chronic, then Rectiv will stop the internal muscle from being in constant spasm which promotes healing. If it is chronic and you've had repeated episodes I suggest you see a CRS so that you are an established patient just in case you need surgery. My wait time for my surgery would have been less if I'd had a doctor already.