My friend just had a colonoscopy & an endoscopy, and has been sneezing violently, along with runny eyes and slight swelling in one eye. The test facility told her they just went to a seminar about people having allergic reactions to oxygen, and that s what she has. Is that possible? She s had over a dozen surgeries, as well as many tests involving anesthesia, and this has never happened before. Is it more likely it was an allergic reaction to the tubing?