Her DS is 12, had a painful testicle on New Years' Eve, NHSDirect said to just keep an eye on it, it was a bit red and swollen but not terribly painful. It's been getting better, looked normal and not painful by Friday.
She just rang me, bit of a rushed phonecall as we were supposed to be going out this morning, she just said "on the way to hospital, DS has a twisted testicle". She's going to ring me when she knows more.
I'm assuming the earlier pain was a 'warning' and he's woken up in lots of pain today... I don't really know. I've googled and everything points to him needing an operation. 
Do I need to dash up the hospital to be with her? Are they likely to actually operate really quickly? Or should I wait for her to call?