Okay here goes:
About 30 years ago, I had an ulcer form in my rectum.
I had to take special granules on the morning of my visit to the hospital (for the x-rays). This was the most powerful laxative I've ever encountered. At the hospital, I was taken to a room where the sister stuck a large tube up my backside. Warm water was pumped into me (most uncomfortable feeling - bloating my stomach till I thought I was going to burst open), then it was released. This was administered several times, with the final one being cold water (even more discomfort than before). The sister was most sympathetic to my plight and couldn't "apologise" enough.
I don't think you would wish to hear what followed from this procedure.
It certainly would not be something I would undertake in your circumstances. I would have thought that IBS and skin problems is something you have because of what you put in (eat), not what you have taken out!