A little blood in the toilet after the second day of coitus may be the normal arrival of menstruation, or it may be caused by cervical disease or vaginal disease. 1. The arrival of menstruation: bleeding on the second day after coitus may be a sign of the arrival of menstruation. There is no clear relationship between the onset of menstruation and coitus. 2. Cervical disease: if a woman bleeds in the toilet the day after coitus, it may be caused by cervical disease, such as cervicitis or cervical cancer, etc. If a woman suffers from cervicitis or cervical cancer, she may have contact vaginal bleeding, such as vaginal bleeding after coitus or vaginal operation, and then further examination and treatment are needed. 3. Vaginal diseases: women bleeding in the toilet the day after intercourse may also be caused by vaginal diseases, such as vaginitis or vaginal polyps, which may cause vaginal stimulation during intercourse and may cause bleeding the day after intercourse. There may be other reasons for a little bit of blood on the toilet after the second day of intercourse, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.