Having diarhea in the shower, most often after a night of heavy drinking and are too tired to make it to the toilet. The phrase is derived from the sight of the loose stool being dissolved away in the shower drain leaving only remnants too large to pass through the grate.
"God, I was so tired I just couldn't make it to the toilet so I ended up panning for gold in the shower"
The perverse and possibly masochistic pleasure of seeking situations that are likely to cause oneself to be outraged or offended, in order to be being outraged or offended by them.
"I just posted this cry-laughing Charltie Brooker quote on Twitter, only to getjumped on by tweeps pointing out my technical inaccuracies."
Don't worry about it, they're just "Panning for turds".