What is Nisus?
1.
the strenuous physical exertion, usually accompanied by some degree of grunting, while sitting on the hopper, and forcing out a stanky, steamy loaf.
This morning upon awakening, I ever-so-gingerly lowered my rompers, sat on the throne, and experienced some vein-popping nisus -- thought my fuckin' eyes were gonna pop out of my sockets!
See