The possible clinical causes of low back pain and small stomach pain include dysmenorrhea, adnexitis, cystitis and so on. 1. Dysmenorrhea: this usually occurs during a woman’s menstrual period, mainly due to the body’s secretion of prostaglandins to promote vasodilatation, muscle contraction, the uterus caused by the extrusion of the symptoms of discomfort, the clinical manifestations of abdominal distension and pain, lumbago, nausea, diarrhea and so on. 2. Adnexitis: this is usually seen in the fallopian tube, ovary secondary infection, clinical manifestations of abdominal pain, vaginal discharge abnormalities. 3. Cystitis: this refers to a disease caused by infection of the bladder mucosa, with clinical manifestations of frequent urination, urinary urgency, painful urination, pain in the bladder area, and lumbar pain. It is recommended that people with related symptoms should go to the hospital to clarify the cause of the disease, so as to carry out targeted treatment.