approximately every 1x10^12 cellular divisions in your body, there is one "mistake" made. most of these -failed cells- are destroyed by your inmune system.
some of them scape your inmune system and become cancer.
Most people who come to the ER with things stuck in their anus are men
I can attest to this since I work in the ER
In my experience it's older men because they don't know what they are doing.