Low back pain with small abdominal pain mostly refers to pain in the lower back and lower abdomen possible causes are excessive exercise, female physiological period, kidney stones, ectopic pregnancy and so on. 1. Excessive exercise: because of strenuous exercise, resulting in mild injury to the lower back and abdominal muscles or lactic acid accumulation, can cause lower back and lower abdominal pain, generally can be relieved by rest. 2. Female physiological period: female physiological period can appear waist and lower abdomen pain symptoms, is a normal phenomenon. 3. Kidney stones: due to stone blockage, damage to the ureter, causing inflammation reaction, can appear in the lower abdomen, lower back pain, pain is more intense, mostly colic-based. 4. Ectopic pregnancy: ectopic pregnancy caused by abnormal implantation and development of fertilized egg can cause pain in the lower abdomen and waist, which is more intense and may be accompanied by vaginal bleeding, nausea and other symptoms. Causes of pain in the lower abdomen and waist are more reasons, may also be related to pelvic inflammatory disease, lumbar disc herniation, tumors and other diseases, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in time, to clarify the cause of the disease, and to carry out targeted treatment.