I am not sure about people living in high altitude but I know if someone with an IBD that travels from a low altitude state to a higher one, the incidence of flaring is greater. I'm proof of that! I live in MI and a few years ago traveled to Flagstaff, Arizona - stayed near Humphrey's Peak. I was fairly stable with my Uc but when I got to AZ, not only did I have a major stuffy and somewhat bloody nose (my family had the same) but I started bleeding pretty good from the tush as well. When that happened I asked on here if anyone else had that and it seemed to be pretty common.
Moderator-Allergies/Asthma and Alzheimer's, Co-moderator-UC
Diagnosed Left sided UC in '92 - meds: 6mp, Colazal, Remicade and Bentyl*Unable to tolerate ALL mesalamines*, in '11 diagnosed with IBS, Diverticulosis, Fibromylagia..I also have Sacroiilitis, Scoliosis, Raynauds, OA, PA, Rosacea, Psoriasis, Dry Eye and allergies controlled by Zyrtec and Singular