Hi Angela. I had this issue all last year and no one had any viable reasons since I was only on Pentasa (yes Flagyl did give me whacked out tastes when I was on it though). What I figured out on my own eventually was that my toothpaste was just too harsh for my mouth/gums/lips. I was using a whitening toothpaste - ProHealth by Crest. I switched to a sensitive version of Crest Pro Health (I think that's the name) that is NOT whitening. I also got rid of the antibacterial mouth rinse that had whitening in it. My tastes have pretty much gone back to normal. I still find I lost my taste for chocolate - but my mom always said our taste buds change as we age...and well I have aged.
I still would ask your docs, but I hope this gives you somewhere to start.