Wiktionary
take a dump
vb. (context coarse slang English) To defecate.
Usage examples of "take a dump".
Herb would drive five miles out of his way to take a dump at the barracks.
Herb had come in from patrol while the lightshow was still going on, probably to take a dump.
And kids can't take a dump anymore but they have to have a helmet and pads on make them look like the Road Warrior.