I used to have that, I think it's just a symptom of UC. I am feeling pretty good lately and I've had somewhat normal BMs.
If I were you, I would try Asacol again, why not? It may not help but it probably won't hurt either provided you're not allergic.
How many pills did you take a day when you took it? I've seen people here taking up to 16!! I take 9 and would like to reduce to 6 but I had symptoms return on 6/day. Asacol took me from constant D and 15 trips to the toilet a day, passing blood and mucus to 1 formed stool a day. I hope you are feeling better soon.