I as well have Ulcerative Colitis and was diagnosed a few years back when i was 22. I've been jumping with UC actively for the last 6 months and thankfully the Humira and other medicine i've been taking to keep that in remission has worked and i haven't had any significant issue. Not too sure when your IBS has issues, but see if there's a certain food you can avoid eating, or see if there's a particular time where it's not as active and go skydiving during those days! When in doubt, keep a bathroom close by!