Pain in the left side of the abdomen with lower back pain is mainly considered urological disease, including urinary stones and urinary tract infection. Further ultrasound examination of the urinary tract and routine urine examination are required, and urine bacterial culture and drug sensitivity test should be performed if necessary. Smaller urinary stones can be treated with medication, while larger stones require lithotripsy or even surgical extraction if necessary. For urinary bacterial infections including cystitis and pyelonephritis, sensitive antibiotics such as cephalosporins or quinolones should be used for treatment.