I've had a rough time with rowasa (generic, which might make a difference), too. I've been waiting to give them a shot once again, but last time I used them, I could barely hold them for 10 minutes. Cramps, gas, urgency, etc.
I get left sided pain around the waist and a little below that I'm sure is UC related.
Aren't kidneys and the pain from infection more above the waist? I've never had one that I know of so I'm not sure.
Potato... Female, 59, dx 11/07 mild left sided ulcerative colitis (50 cm), 10/09 condition has "considerable worsened" (per my GI) to pancolitis
Currently on Pred 15 mg, tapering, Asacol 3 3x a day, Imuran 150 mg and coming out of the last flare
primadophilus reuteri, children's Centrum, slow FE
omeprazole 2xday, oxazepam when needed, lomotil
Already tried: Colazol, Hydrocortisone enemas, Rowasa, spinach and sunflower diet (helped but didn't get me in remission)