Another way that an individual can express that they need to defecate much like saying they have to "pinch a loaf". This is a reference to the candy land character, Mr. Gloppy the chocolate monster, and as he looks like a giant turd it fits rather well.
1. Carl went to hit it last night but she had that gloppy jalopy, so he dipped.
2. Carl: Damn it smells like fish in here.
Steve: No that's just Samantha's gloppy.
3. Does she have some fresh poontang or that gloppy jalopy?