Some foods irritate the anus when they are expelled during a bowel movement. The most common culprits are
caffeine, chocolate, beer, nuts, dairy products,
and spicy food.
Infections such as pinworms, yeast, and genital warts can cause itching.
Hemorrhoids, which cause painful swelling of blood vessels in the anal area, can cause itching.
Cancer, in rare instances, may be a cause.'
There are certain factors which predispose to the risk of developing anal itching as a symptom.