Doctors have documented numerous cases of insertion of foreign bodies into the urethra

Urethra

In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...

, typically as the result of auto-erotic activities. This can result in serious medical problems.

A wide variety of objects have been observed to have been inserted including batteries, safety pins, straws, and telephone wires.

The Chuck Palahniuk

Chuck Palahniuk

Charles Michael "Chuck" Palahniuk is an American transgressional fiction novelist and freelance journalist. He is best known for the award-winning novel Fight Club, which was later made into a film directed by David Fincher and starring Brad Pitt, Edward Norton, and Helena Bonham Carter...

 story "Guts", from the novel Haunted, includes the story of a boy in his early teens inserting candle wax into his urethra.