Remicade does wonders, with minor setbacks

I had severe colitis, was on Prednisone, Asacol, Canasa, Lialda, Aprisa, and all had little or no effect. I slowly responded to high dose steroids in the hospital for over a week in May and transitioned into a full recovery on Remicade. I have been on Remicade since May (stopped all other meds) with a virtually worry-free life. I'm healthy, awake, eating most anything, and going to the bathroom appropriately (1-2 times a day, solid, no blood noticed).

I have been in remission, but there have been a couple occasions when I noticed blood in excess in a 2-3 day span, then it would go away. I haven't figured out if there is something I'm doing (drinking a lot of soda, exercising, having a beer) that could trigger it, or something else. There is no pain or other symptoms with these instances– I just don't want them to stick around and need a new treatment. The blood has occurred a few days after infusion, and twice sporadically in between, so I don't think it has to do with Remicade treatment times... I am on Day 3 of bloody stool and hope that it will pass.

Do you have any advice from your experiences? Are these little flares normal? Or acceptable?