When you have to shit so much that you cannot physically shit all of it in one sitting, and need to take a break while the rest of the shit queues up in your intestines. The waiting period can be any amount of time between 20 minutes and a couple of hours, and usually the shit can be completed in two sections, though it may take three or more with epic shits.
"Just a sec guys, I gotta shit"
"Dammit Chris, what the hell is wrong with you? You just went to shit like 20 minutes ago!"
"Sorry boys, after all that shitty beer and T-bell last night I gotta take a sectional"