The pelvic effusion can cause abdominal pain, at this time should promptly go to the hospital for examination, generally considered to be caused by pelvic inflammation, ectopic pregnancy, pelvic and abdominal tumors, etc. After clarifying the causes of pelvic effusion, targeted treatment under the guidance of doctors. The common causes and treatments 1, pelvic inflammatory disease: the disease is often triggered by menstrual periods do not pay attention to hygiene, when the endometrium is shed, the uterine cavity blood sinus is open, when the bacteria invasion, easy in the warm, nutrient-rich environment overproduction, triggering inflammation. In this case, it is necessary to use antibiotics for treatment, such as metronidazole, and to avoid sexual intercourse during treatment; 2. Ectopic pregnancy: If you have recently had sex without contraception, you need to consider that it is triggered by ectopic pregnancy. After the rupture of ectopic pregnancy, blood flows into the pelvic cavity, forming pelvic fluid, which in turn leads to abdominal pain. In this case, immediate medical attention should be sought to avoid dangerous complications such as hemorrhage. During the treatment period, patients are advised to maintain a stable mood and avoid depression and other bad emotions. 3. pelvic and abdominal tumors: due to the increase in vascular permeability caused by tumors, fluid filtration increases, resulting in more fluid accumulation and abdominal pain, which is often treated by surgical removal. In addition, it is recommended to eat more fruits and vegetables in daily life to increase the intake of various nutrients and enhance physical fitness. In addition, endometriosis can also lead to pelvic fluid accumulation, which in turn can cause abdominal pain. In this case, Denogestrel can be taken under the guidance of a professional doctor to relieve the symptoms.