Diflucan is an anti-fungal drug. It's used to treat thrush and vaginal yeast infections.
Also, please notice that he doesn't say he's "cured" but that he's "healed." So am I. So are many of us who are in remission. The UC is still there, but is not active, and the lining of the colon has healed. The UC can still come back, and likely will at some point.