This is because during intercourse, the male penis pumping will produce intense stimulation to the female vagina, abdominal cavity and pelvic organs, causing vague pain in the abdomen, which often occurs after sex and is generally tolerable and will disappear on its own, without treatment. The vague pain in the abdomen after intercourse is also often seen during ovulation, pre-menstrual period, inadequate vaginal lubrication, improper sexual lifestyle and pelvic inflammatory disease: 1, ovulation: a few people will have mild abdominal pain during ovulation. Symptoms, at this time intercourse will aggravate the discomfort, generally do not need treatment; 3, vaginal lubrication is not enough: not enough preparation before sex, resulting in insufficient vaginal secretion, vaginal dryness, vaginal and lower abdominal pain caused by strenuous friction during sex, generally rest can be recovered; 4, improper sex life: too violent movements during intercourse, excessive force or improper position resulting in vaginal damage, as well as the uterus, rectum, bladder by gravity. The bladder is squeezed by gravity, which is manifested as vague pain in the abdomen. If the symptoms are mild, they can be relieved after rest; if the symptoms persist, it is recommended to seek medical attention to clarify the damage and carry out treatment; 5. pelvic inflammatory disease: pain in the lower abdomen is the main symptom, which can be persistent and often intensifies after exertion, intercourse and before and after menstruation. It is recommended to take oral antibiotics for treatment as prescribed by the doctor, and drink more water during the medication to promote the dissipation of inflammation. Pay attention to hygiene before and after sex, and do not move too vigorously during intercourse. If the pain in the abdomen does not subside after intercourse, it is recommended to seek medical attention.