Hey glad I've come across this thread. I've had problems peeing when I've had a couple of my relapses this year and a few weeks ago I was retaining urine and had to be admitted to hospital and had a catheter fitted for 5 days. I had the same problem with my bowels too.
I am following the swank diet so eat a lot of fibre anyway but even that wasn't helping. I had steroids to help clear up that relapse but my bladder and bowels were still not too good.
One tip a friend of mine gave me was to eat a juicy piece of fruit (I had pineapple) when you first wake up before breakfast. It really did work for me.