my answer will probably not help much... I have had flares that have lasted 2 days but also had some that were over 2 weeks... for me I find that if I do too much I always suffer the following day but sometimes it will trigger a flare. by sticking within my limits, not allowing anyone to push me beyond what I can do will usually keep me okay.

It can be anywhere from a few days to a few weeks. depends on your stress and anxiety levels. And it is different for everyone. I feel like I have been in a flare for the last 8 months, but my stress and anxiety levels are really high and I have developed unusual symptoms that they are still trying to diagnose.

i do not have flares.My pain is 24/7.