Darkwaters........ Just after my takedown, I experienced similar experience as yourself, absolute agony, although there was no soreness to the skin between the cheeks.
I got instant relief by applying a small pea size amount of ilex Protectant Paste to the tip of my finger and appying it slightly to the inside of the anus.
I discovered some weeks later, that during takedown Surgery, what remains of my anal canal or where it once was, required dilation; I believe the dilation created anal fissure and as a result; it felt like passing hot razor blades during a BM's...... the ilex paste alleviated this.
Its been months since my takedown and initially, from time to time I used to experience the same sensation and pain which was always alleviated by the application of the ilex paste.
Although, on the box and ilex tube, it says.....For External Use Only.
I mention to my Pouch Nurse and explained how I've been using it and she said it's ok but don't apply it excessively or too deep.