Threadworms are also commonly known as a pinworm or Enterobius vermicularis. These small, white parasitic worms infect the intestines and rectum of humans. Other synonyms for threadworms include seatworm, itchy bottom worm, or anal worm. Infection with threadworms can cause itching and discomfort in the anal area, especially at night when the female worms lay eggs on the skin. Threadworms can easily spread through contaminated surfaces, such as bedding or clothing, and can pass from person to person through contact. Treatment for threadworms typically involves a single dose of medication, such as mebendazole or pyrantel pamoate, and good hygiene practices to prevent re-infection.