For those who got addicted to a flowing-water toilet shower and now can't (or don't want to) take a dump on a public restroom, don't worry, us Germans got y'all covered with the portable butt cleanser [1].
As a side note, you can get that product at online retailers by searching HappyPo, as it appears the english website is currently down.
It collapses, I just throw it into my luggage whenever I'm traveling.