A workstool is the shit you take at your place of work, usually on purpose to take a break and always on the clock. The verb form of workstool is workstooling which can refer to the actual action in the bathroom or to intentional rationing of bowel movements at home in order to wait till you are at work and clocked in.
A: "Hey where did Josh go? He's supposed to be moving crates to the basement!"
B: "I think Josh is busy with a workstool."
A: "Why don't you take a shit and stop complaining about how bad you have to go!?"
B: "No can do partner, I have night shift."
A: "Why does that matter?"
B: "I'm workstooling."