Credit to: No Such Thing As A Fish Podcast.
On one of the latest podcasts Harkin descries that with the Mate Tea (a very fine particulate tea) you can get upstream movement of particulates. "The tea leaves climb back into the kettle"
This references: http://arxiv.org/abs/1105.2585 S. Bianchini, A. Lage-castellanos, E. Altshuler (Submitted on 12 May 2011)
The phenomenon was ﬁrst observed during the preparation of the typical
Argentinian drink, mate, when hot water was poured, from a pot, on a
water surface “contaminated” with ﬂoating mate particles (each
particle is like a grass leave of an average area near 0.5mm^2 If the
column of falling water was short enough (say, under 1cm-height),
particles of mate were observed to “swim up the stream”, actually
reaching the originally “uncontaminated” water pot.
The study continues:
For distances of the order of 1 cm or less, some of the ﬂoating
particles eventually start to “climb up the stream”
Unless you were peeing 1cm away from the urinal, it's not possible for it to climb your pee stream.
(Your doctor might have been referring to "witches kiss" where your todger touched the ceramic of the bowl while sitting down)