A malady common to carbon-based life forms, cranio-rectal intrusion is also known as having your "head up your ass." As the size of any bureaucracy or institution grows, an exponential increase in the number of cases of "cranio-rectal intrusion" will also occur.
With no repercussions ever being suffered for not following the very laws it institutes, the U.S. Congress continues to prove that the people of the U.S. are suffering from a level of apathy that can only be achieved by prolonged cranio-rectal intrusion.
One who explores another person's anus, with fingers, penis, or other instrument with such enthusiasm as if they were rummaging around for something in there. Also used as a playful insult of a friend, like calling them a penile perpetrator, fgt, or scrotum soldier.
"STFU you rectal rummager! I heard bout what you did to that other guy when you were drunk at the party, you fgt!"
When one of the female co-workers freaks out over being "underpaid" for the umpteenth time. They are lucky to have any job at all after calling in sick so much.