Actually, googling that to check the spelling - which I probably still got wrong - I came across this:
Post-micturition convulsion syndrome, also colloquially known as pee shivers, piss shivers, piss quiver, quiver shivers, the timely twitch, or the shiver shake, is a phenomenon in which one feels a shiver running down the spine following urination.[1] The shiver can produce a brief twitch, which is a form of myoclonus. It should not be confused with micturition syncope, a feeling of faintness following passing urine.
To date, despite years of discussion and theorizing, there is no agreed-on explanation of the phenomenon[2] and no medical research into it. However, it has been mentioned occasionally in columns, and in one Internet poll, where about 83% of males and 58% of females reported experiencing it. By 6 July 2007, more than 24,000 males and more than 1,200 females had responded to the poll on the syndrome.
Fancy, etc.