[hussong]

There's also "Heimscheißer" -- someone who strongly prefers taking a dump in the comfort of his own home, and may even be incapable of doing so elsewhere, except for emergency situations.

[1wd]

Since that word is somewhat noted for its use in the German dubbed movie American Pie, I just wondered what the original uses instead. Apparently: http://www.urbandictionary.com/define.php?term=shitbreak

[wolfgke]

Or "Gehemmtpinkler" - a person that is unable to urinate at an urinal if he thinks that somebody might be looking at him or even is in the same room.