I have been a high school and middle school teacher for nearly twenty years. I chose to teach these upper grades because I figured my students could handle their bodily fluids on their own (primary concern v*, of course). In ALL my years of teaching, I've encountered evidence of v* on a toilet once, the smell of v* coming from a bathroom once, and v* on the grass outside on two separate occasions. I told the custodial staff right away each time, and it was dealt with immediately. I've also heard about it happening in various places but wasn't present to witness it. I've never actually seen any of my students v*. So four encounters with v* after the fact in 20 years isn't so bad. Believe me, if a student of mine told me that have a phobia and asked to sit by the door, I would completely sympathize. I'm sure there are multiple phobias that would require a person to sit by the door for a quick escape route in order to feel safe.