Late last year I found a new GI that told me to stop taking Pentasa. He said that it did nothing to help maintain remission with the Crohns I had. I didn't ask him much about it, just happy that I wasn't taking 12 pills a day. So apparently in one way or another it's been determined that Pentasa does not treat Crohns at least in the area I have it (terminal ileum).
Glad I paid out all those co pays for something that serves no purpose.