I just had a colonoscopy 3 weeks ago. Well they found a polyp and a tiny ulcer. But when these got to the lab the vial supposed to have the ulcer sample had a polyp and the vial supposed to have the polyp was empty. So as luck would have it the DR. informed me of this mix up and wants to re do it. And guess what day he informed me of this? Can you say friday the 13th ! Well as medical mistakes go this was minor but still sucks!