Trench Edging

When you are taking a shit, and you let the turd about halfway out, but then suck it back in and repeat the process. Typically used as a method of self-punishment, similar to regular edging.

A: "Bro what took you so long to get back on the game? You were gone for like an hour."
B: "Sorry bro, I was busy trench edging myself, I've been hating myself a lot recently."