Squinch Marks
Noun (plural) - marks left across ones butt cheeks (usually brown) horizontally protruding outward from the anus, caused by prematurely pinching off a full loaf in mid-squeeze. This usually results in "mud-butt" and "sticky cheeks".
Michelle heard Robin screaming about something mindless in the office, and was forced to pinch off a fat loaf, resulting in squinch marks for the duration of the day.