If there is a pain in the anus during menstruation, it is advisable to take oral pain medication, such as Fenbid, to relieve the pain. It is also advisable to have an examination after menstruation to find out if there is an endometriosis lesion in the rectal mucosa. If the endometriosis is localized in the rectum, it is possible that the ectopic lesion will bleed with the shedding of the endometrium during menstruation, so there will be a burst of pain, and the pain will seriously affect daily life and work. If this is indeed the case, it is recommended to actively give treatment, and you can intrauterine Manned IUD. The main purpose is to make the endometrium shrink, then the ectopic lesion will also shrink, so as to achieve the purpose of treatment.