Normally we dont allow testing questions but thats more about passing, what they test for, etc. As this is a physical issue I feel its a bit different and warrants some discussion, at least direct experience and suggestions.
I was on probation from 2008-2010 luckily i managed to get my PO to understand that I wasnt trying to fool anyone and i just couldnt pee with other people in the room. This happened because i was vocal about it but not trying to stop them. When they sent someone with me i literally said in front of everyone "nice to meet you... you probably want to get a news paper because i wont be able to go, at all" and then after 30 minutes of "what if you flush the toilet, what if you run the water what if you..." i tried it all and finally the second they were like "whatever" and started to close the door *bam* urine sample.
I cant say thats normal but somehow it worked, other wise id probably still be standing there from 08 till now, i cant go if i know someone is watching me its like a mental thing i can not get over. This is partly why i need to avoid prison and places that thing is forced upon you, i really dont know what would happen i guess i would get over it. I mean i would have to.