Are you leaving the Rowasa in all night when you do your nightly dose? I have found that that gives me terribly runny icky poops the following morning. Its like the medicine turns whatever is in there to mush. So now I do 30 minutes and go to the bathroom and let it empty out and then go to bed. This really seems to help the problem of consistency.
I always thought the more time I could keep the meds in the better, but that doesn't seem to be the case with enemas. I share your frustration with not understanding this stuff. There's so much trial and error to sort through. Good luck!