The following causes are common in clinical practice: 1. Chronic pelvic inflammatory disease, because the pelvic cavity itself is congested, adherent, and edematous. The stimulation after intercourse will aggravate the edema and congestion, so pain in the lower abdomen will occur, and because the inflammatory tissue is relatively fragile, a small amount of endometrial tissue will be shed and cause vaginal bleeding. 2. Endometriosis can also cause stomach pain after intercourse, and is accompanied by a small amount of vaginal bleeding. 3. lesions, or due to cervical cancer, can lead to bleeding during intercourse. As the chronic inflammation of the cervix is the sacral ligament is affected, so it can also lead to stomach pain after intercourse. It is advisable to have a detailed gynecological examination to find out whether there is pressure pain in the uterine adnexa and to know the exact site of bleeding, and screening for cervical cancer is also recommended.