While I have been told that stress does not actually cause a flare
I have also read this and also think its b.s. Everyone I know with IBD says it is always the worst when they are stressed, although it may be one of those chicken/egg arguments. Along with the other great advice you've already been given, I think the best way to deal with stress is exercise. Since being diagnosed, I've found that really heavy and hard workouts wear me out too much, but what I would call 'medium intensity' workouts are great. If you can find team or group exercises, even better. When I play team sports, I never once even think about
my stomach problems.