Irregular echogenicity of 15.6 x 16.5 millimeters is seen in the uterorectal sulcus, indicating a small amount of pelvic fluid, which needs to be treated for the etiologic factors leading to pelvic fluid. Pelvic fluid caused by physiological factors does not require treatment. Pathological factors such as pelvic inflammatory disease, ruptured ovarian cysts and other diseases that lead to pelvic fluid need to be treated with medication or surgery. 1. Physiologic pelvic fluid: If a small amount of pelvic fluid is found during menstruation or ovulation, it may be a physiologic pelvic fluid, which will not have any effect on the body and does not need treatment. 2. Pelvic fluid caused by pelvic inflammatory diseases: if the patient has excessive leukorrhea, abdominal cramps, lumbago and lumbar pain and other uncomfortable symptoms, ultrasound found to have a small amount of pelvic fluid, it may be pelvic inflammatory diseases. In this case, you can use metronidazole and levofloxacin and other drugs under the guidance of the doctor for treatment. 3. Fluid accumulation caused by ruptured tubal pregnancy or ruptured ovarian cyst: If the patient has severe pain in one side of the abdomen, consider whether there is a ruptured tubal pregnancy or ruptured ovarian cyst. If this is the case, surgery may be needed.