We are all different, so find out what works for you.
Metamucil (part of the Anderson program) is terrible for me-- causes non-stop clustering.
Imodium generally works better for me at slowing things down than Lomotil and doesn't make me as sleepy.
Prune juice causes me diarrhea... even just a little.
I got a Biobidet-type toilet seat and haven't had any butt burn issues since. It is wonderful! I forget which brand and model-- can check it if you are interested.
I try to have a lot of SOLUBLE fiber- namely oatmeal and apples. Seems to help. I use the real, cook from scratch oatmeal, not instant. I just put it in the rice cooker before I go to bed, put on the timer and wake up to fresh, hot oatmeal! I add frozen blueberries and nuts.
You are really early in the process and what you are going through is normal, but experiment with cutting out the prune juice and see what happens. Also the benefiber or metamucil works wonders for some but for me it just kept me going and going and going and...