There are two main reasons for back pain and abdominal pain after intercourse: First, physiological, vigorous activity during intercourse will produce stimulation of the vagina, abdominal cavity and pelvic organs, due to the sexual excitement at the time to mask the pain, will be in the intercourse a few hours after the pain will show, back pain and abdominal pain is temporary, will gradually eliminate. Second, pathological, caused by gynecological inflammation or luteal rupture. Gynecological inflammation such as cervicitis, adnexitis, pelvic inflammatory disease, recurring under the stimulation of intercourse, will cause pain in the small abdomen or lumbago and back pain, and there may also be a small amount of vaginal bleeding. The pain lasts longer and does not disappear with the end of sexual intercourse. Luteal rupture is caused by the rupture of mature follicles and corpus luteum during intercourse by squeezing and vibration to form abdominal bleeding, which stimulates pain in the abdomen and lower back, and prompt medical attention is recommended.