After inserting the Mirena IUD, if menstrual bleeding persists for three to six months post-insertion with minimal flow and no significant discomfort, this is considered normal and typically requires no intervention. The Mirena IUD is a new type of intrauterine slow-release system, essentially a hormonal IUD. The hormone contained within it is primarily the highly effective progestin, levonorgestrel, used to treat gynecological conditions such as heavy menstrual bleeding, endometrial hyperplasia, post-surgical treatment of endometrial polyps, or adenomyosis. After insertion, doctors will inform patients that symptoms of prolonged menstrual bleeding may occur within three to six months, which is normal. A follow-up examination to check the IUD position should be conducted one month after insertion. However, if prolonged bleeding continues beyond six months, it may indicate displacement of the IUD or that the Mirena IUD is not suitable for the patient, necessitating prompt follow-up and appropriate treatment.