If a woman experiences anal swelling and vague pain in the lower abdomen, the most common cause is chronic pelvic inflammatory disease. As there is chronic inflammation in the pelvis, it can lead to more exudation from the tissues, and the exudation tends to flow to relatively low locations in the body, for example, in the pelvic uterine rectal sink which is a relatively low location where fluid can collect and stimulate the anus, causing a local feeling of swelling. In the lower abdomen, vague pain can also occur because of the decreased elasticity of the tissues in the pelvic cavity. In this case, once the inflammation of the pelvis is diagnosed, anti-inflammatory treatment should be actively given, and nutrition should be strengthened in daily life to increase resistance, which will help the inflammation to be absorbed as soon as possible. It is also necessary to exclude the symptoms caused by the rupture of the corpus luteum, which often occurs in the second half of menstruation. Ultrasound examination can make a preliminary diagnosis and then give treatment.