Pinworm. Scotch Tape applied to the anal area first thing in the am will pick up deposited eggs, and diagnosis can be made by looking at the tape with a microscope. The eggs are not laid in the stool but are stuck on the anus, readily available to be picked up on fingers to be spread.
Being human usually suffices.
Itchy butt.
A 100 mg of mebendazole repeat after 2 weeks.
Pinworm eggs have been found in fossil poo, carbon-dated to 7837 BC in western Utah, but no fossil scotch tape.
Last update: 05/05/18