After intercourse, if the belly appears swollen and painful in the clinical most common is the following two causes, one, pelvic inflammation caused by inflammation, then the tissue elasticity is reduced, intercourse will stimulate cause pelvic congestion, the original inflammation will appear pain. Second, caused by endometriosis, so that the ligaments and pelvic tissues in the pelvic cavity are adherent, and when intercourse is stimulated by the outside world, it will lead to pain. So if you have stomach pain after intercourse, it is best to go to the hospital to give an examination. First of all, a gynecological examination should be done to find out if there is any inflammation in the pelvis, and if there is, anti-inflammatory treatment should be given in time. Secondly, it is also recommended to have an ultrasound examination to find out if there are foci of endometriosis in the pelvic cavity and then give treatment according to the results.