i have a history of pancolitis but in patches throughout my colon. i used lialda (i think this is similiar to mezavant, if someone can chime in) which cleared the top part of my colon and i religiously used rowasa which cleared my rectum, and i was left with about a 4 inch isolated patch of inflammation in my sigmoid. in my opinion, this is the spot that the lialda and rowasa couldnt reach.
my flare started in 2008 and by 2012, still flaring, nothing could heal up the inflamed part of my sigmoid. ( believe me i tried almost everything). i was still having about 6 bms with blood and urgency a day. my gi suggested imuran, she didnt force it on me.
i weighed my options, and i felt the constant inflammation in my sigmoid was as bad or worse than the risk of cancer. so i took a chance on imuran, with the idea that i could stop if i wanted to and meanwhile other drugs may come out.....
anyway, i started imuran june 2012 and i am at about 98% now, with anywhere from 3-4 bms, formed, with blood every once in a while, very mild urgency, can hold till i get to a bathroom) thats ON imuran!
your symptoms sound really really mild to me, given what your scope says. i might try a few other things first if i were you such as, increasing your oral med 5asa to the highest dose, and maybe looking into that new entocort like drug.....
good luck.....