I also have urgency issues when taking mesalamine (which is why I now take my Lialda at night), but I haven't had any issues with Rowasa as long as I use it at bedtime.
I missed a dose one night so decided to use an enema in the morning and figured I'd lay on the couch for a while before leaving to run errands. After about 20 minutes I had to bolt to the restroom. I used the restroom 3 or 4 times before finally feeling well enough to head to the grocery store. I got on the road and had to find a gas station within a few minutes to use the restroom yet again.
In any case, you're not alone in the urgency dept - however if I use the enema at night I have no effects the next day. Is that what's happening to you?