The following are some of the reasons for the lower back pain with abdominal distension: 1. Urological diseases need to be ruled out, the common ones are like cystitis, the patient will have more obvious urinary symptoms in the acute stage, like frequent urination, urgent urination, painful urination and even hematuria, also accompanied by lower back pain, abdominal distension, pain in the perineum, and accompanied by increased body temperature, and can be frequent. Patients with chronic cystitis may not be accompanied by more obvious clinical symptoms, vague pain in the waist, small abdomen, perineum, systemic symptoms and urinary symptoms will not be too obvious, and can be diagnosed by urinary routine. 2, seen in nephritis and other kidney diseases, its pre-episode can also be manifested as weakness, waist pain, small abdominal distension, no appetite, and even reduced urine output, with progressive aggravation of the disease, there will be anuria, general 3. Abdominal distension caused by simple lumbar diseases is rare, but it can be seen in lumbar compression fractures caused by trauma, where patients have more intense pain, and abdominal distension can be triggered by increased abdominal pressure due to lumbar fractures, mostly with a history of trauma.