Men’s left lower abdomen pain may be trauma, ulcerative colitis, intestinal obstruction, ureteral stones and other reasons. 1. Trauma: men are prone to skin abrasions, impact injuries, crush injuries and other traumatic injuries in dangerous outdoor work environments, driving, etc., which can lead to skin or intra-abdominal tissue injuries when involving the left lower abdomen, causing pain in the left lower abdomen. 2. Ulcerative colitis: non-specific inflammation of the descending colon, sigmoid colon, rectum and other parts of the body leads to the formation of ulcers, causing pain in the left abdomen. 3. Intestinal obstruction: Mechanical blockage of intestinal tract, abnormal intestinal dynamics and other factors lead to intestinal obstruction, poor fecal discharge, increased pressure and left abdominal pain. 4. Ureteral stones: the lower part of the left ureter is shaped in the pelvic abdominal cavity of the left side of the abdomen, when the stone formation due to urinary tract obstruction leads to pain in the left lower abdomen. Men’s left abdominal pain may be related to a variety of factors, it is recommended to consult a doctor to clarify the diagnosis.