The common causes of stomach pain after intercourse are vaginitis, cervicitis, cervical erosion, pelvic inflammatory disease, too much force during sex, etc. First of all, women suffering from vaginitis is not timely treatment, is the mucous membrane of the vaginal wall is in a congested, edematous state, during the vaginitis sexual intercourse, the mucous membrane of the vagina produces friction, it is easy to have a burning sensation of the vaginal area after sex, the pain in the lower abdomen. Secondly, if a woman suffers from cervicitis or cervical erosion, the penis stimulates the cervical area to cause pain or bleeding when having sex, which leads to stomach pain after intercourse. Then when a woman suffers from pelvic inflammatory disease, the pelvic mucosa is in a state of congestion and edema, and stimulation of the cervical region when having sex will aggravate the symptoms of congestion and edema of the pelvic organs, so there will be tummy ache and lumbar pain during sex. Lastly, if men exert themselves too much during sex, they are prone to stomach pain afterward, which lasts for 2-3 days and can be relieved on its own.