ah ha! Kindred spirits! I also have gi issues and am a distance runner - go running 4+ hrs at altitude on the w/e. I have had the dreaded upper and lower gi scope... not fun at all! They didn't really find anything with me... I think it's stress induced (graduate school was not kind to me). Good to know that my running could also be a culprit. I'll keep that in mind the next flare up I get