@ DSZ: Hi, yes, I've been there. I had my jpouch removed in October (ulcerative colitis, 2 step jpouch in 1995/1996) after having it for 18 years. I also had my anal closure done at the same time as having my jpouch removed and perm ileo installed.
At two months post op I was doing much the same as you. I would have a good one or two days and think, gee, this butt thing is healing up ok. Then BAM I'd get a bad day. I only took tylenol (extra strength) - but there were time I needed to take 4-6 a day.
My sutures were dissolvable, the first few weeks I couldn't feel a thing to be honest, then after about week three the sutures were drying out and it would get uncomfortable for me. I was told by my surgeon not to soak in the tub or have sitz baths as she did not want the sutures to dissolve before they were ready to. So, I would shower in the morning and pat the area dry with gauze, then at night I would use a squirt bottle to clean the area and dry again with gauze.
I am now over 5 months post op and everything is healed up. If I "spread the cheeks" and take a look, it just looks like a thin line, nothing is obvious and it feels ok to sit directly on it.
I do get phantom rectal pains daily, but they are less intense as the months go by, and they occur mostly when I'm walking or at the gym doing cardio. Could phantom rectal pains be part of what you are experiencing? The best thing for me to do when a phantom pain is coming on is concentrate on breathing and not pushing my butt muscles. If it's a really bad one, I will go sit on the toilet and it helps. They are lasting less than 10 seconds now, and my surgeon said that some people will always have them, and some people will never have them, but the important thing is NOT to give in to the feeling of having to push.
I didn't buy or use any seat cushions. I would just sit one cheek, then the other. I would lie down on the couch or my bed often.
Also, two things that really helped were walking daily, two or three times if I could, this strengthens the muscles that they cut up and gets blood circulating to the area. The second thing I would do, and it sounds strange, is once the butt incision healed I would put vitamin E (just buy softgels and poke a hole in them) on my hand and massage my butt crack. That helped break up the forming scar tissue and it's really soft down there, I no longer feel like I'm sitting on a tennis ball.
I hope my post helps you some, please keep me updated.
Diagnosed with UC in 1990 at age of 10
Proctocolectomy with temp ileo and jpouch creation 1995
Ileo take down 1996
JPouch removed, butt closed and perm ileo 2013
Happy and healthy future!