Metamucil or the generic equivalent is good for firming the stool as it sucks the water into it and bulks up the stool. It comes in the powder like form, the powder into the clear clear gel caps and there are metamucil wafers that many like to eat. Others prefer products like Benefiber instead.
My surgeon had me using both fiber and imodium together and I gradually cut back on them until I didn't need them anymore. I still used imodium when needed. I still need pain medicatiom that contains hydrocodone which slows things down.
If I were you I'd start out with the wafers or fiber filled gel caps. I would used 3 caps 3-4 times a day along with generic imodium. One service is 5 caps or 1 tbls if you want to mix it in water of juice. When you use it to bulk up your stool, like us, you should use less water than instructed at the time you take it. That doesn't mean you should decrease your intake of water during the day but take the amount you need to swallow the fiber is all that is needed at that time.
It is a more natural way of helping things along, per my Internist. I still don't have well formed stools as I find it easier to completely empty my pouch when things are looser.
I think I told you before but I have permanent neuropathy in both of my feet and the cause is unknown. As you can imagine I am less than thrilled to be taking Flagyl currently
If you do a word search on fiber there are some good past threads about this and you can see how other people dosed their fiber and what they used.
Other stool thickeners I like are bagels, marshmellows, bananas and potatoes.
I've tried all kinds of ointments and lotions and my favorite is calmoseptine. I first bought it at Walgreens, sometimes you need to ask for it at the Pharmacy. Now I order it 6 tubes at a time at Amazon as I still get it from time to time with my cuffitis and/or c.diff.
I hope you get over your butt burn soon.