Oreo

When doing a poo, one begins wiping but then realises they need to finish the job and subsequently poo on top of the toilet paper, thus creating a tri-layer work.

The formation of the ordeal goes:
brown
white
brown

Typically occurs when the bowels are volatile and unpredictable (ie. diarrhea).

Oh boy, after all that curry I just ate, I couldn't help but go do an Oreo in the toilet!