Showter

(verb) The act of shitting in the shower.

Dude, I was holding my shit and went to take a shower but I totally showtered. There was shit everywhere!

showter

Someone who shits in the shower while intoxicated

"You're a showter sir!"
"Who was the big showter last night?"
"I swear I'm not a showter! Although, I did wake up in just my boxers this morning......Nah, it definitely wasn't me!"