There are many reasons for brown discharge after menstruation. This condition is generally not considered to be a precursor of cancer, but may be caused by unclean menstruation and other reasons. If brown discharge appears 1-2 days after menstruation, it may be due to unclean menstruation. If brown discharge appears more than 1 week after menstruation, it may be due to a small amount of bleeding during ovulation or local inflammation of the cervix. Generally, there are no obvious symptoms in the early stage of cancer, and a few patients may have irregular guiding bleeding, which may also be accompanied by abdominal pain and other manifestations. It is recommended to visit the gynecology department of the hospital to improve relevant examinations. Some women may have intercourse after menstruation, which may stimulate the endometrium that has not fully recovered, resulting in irregular shedding and a small amount of bleeding, so there is no need to worry too much. In addition, displacement of the IUD may cause irritation to the surrounding endometrium, which may also cause brown discharge after menstruation. Brown discharge after menstruation may be a precursor of cancer, but it is rare. Early symptoms of cancer usually include irregular vaginal bleeding and incomplete bleeding, which need to be diagnosed based on relevant examinations, such as cervical cytology, ultrasonography and sex hormone test.