Hi,
Welcome to the ehealthforum and I am really glad to help you out. It can be an infecetd hair follicle, boil, abscess, anal fissure or cyst. Apply warm compresses and keep the area clean.Drainage of the boil is done only when it becomes soft and forms a head.Take some over the counter pain reliever and consult a doctor for examination and antibiotics prescription.
I hope it helps. Take care and regards.