First of al Flagyl=absolutely no alcohol intake. I won't re-tell the whole story, but one french fry that was beer battered made me violently ill and sent me to the ER when I was on flagyl. Flagyl also has potential for neuro side effects that you should discuss with your doc.
I also wonder why flagyl is being considered as a maintenance med for you. Do you have fistulas? I would get more info form your doc on why this is the protocol he recommends
I have not taen 6mp so I can't address that for you.