Yes, the company that manufactures Asacol has replaced it with Delzicol. There is a press release that states the company was required to pull Asacol after approval of Delzicol. As another member posted, the patent for Asacol will expire July 2013. As you can see from the press release, Asacol accounts for $743 million of the company's revenue. So, it seems they did not want to lose that money. I still do not fully understand the rationale for creating a new branded drug; it is possible that the generic asacol will not be able to be released by other companies because it has been withdrawn from the market. I simply do not know.
The active ingredient is the same between Asacol and Delzicol. There are 2 inactive ingredients that have changed, according to the full prescribing information for both drugs. I happened to look into this today when my father called because he received a letter from his pharmacy. He has Crohn's disease and I have ulcerative colitis. We both rely on our asacol very much.
http://www.reuters.com/article...dUSBRE9170PB20130208