You really need to get your symtoms under control. Pentasa will not do it. If fact, many GI's won't even prescribe Pentasa anymore, as very few believe it's of any use.
You need to consider a course of Prednisone, then choose a follow-up maintenance therapy. You should consider either Imuran/6MP, methotrexate or Remicade/Humira.
You'll have to do a considerable amount of your own research. Hopefully you get on top of things soon.