Pain in the left lower abdomen, be alert to intestinal diseases, urinary system diseases, intra-abdominal diseases, female reproductive system diseases, abdominal wall diseases. 1. Intestinal diseases. Including acute enteritis, Crohn’s disease, tumors in the left half of the colon, low intestinal obstruction, etc., all of which may cause pain in the left lower abdomen with abnormal stool. 2. Urinary system diseases. The common ones are urinary tract infection, left ureteral stone, bladder tumor, etc., which can also cause pain in the left lower abdomen, accompanied by abnormal urine routine. 3. Diseases in the abdominal cavity. Infections in the abdominal cavity, tuberculous peritonitis, etc. may also cause pain in the left lower abdomen, which may be accompanied by pressure and rebound pain. 4. Diseases of the female reproductive system. Left ovarian cyst tip torsion, uterine tumors, etc., may also appear in the left lower abdomen pain, can be diagnosed by ultrasound examination. 5. Diseases of the abdominal wall. For example, injury to the abdominal muscle, left inguinal hernia incarceration, also prone to the left side of the abdomen pain. If you have pain in the left lower abdomen, go to the hospital in time to check and diagnose the disease before treatment.