The most common diseases that cause left lower abdominal pain in men include the following two: i. Ingrown inguinal hernia, which is mostly seen in infancy and early childhood due to crying in children, causing increased abdominal pressure. In the elderly, chronic prostatic hyperplasia and chronic coughing can cause the abdominal pressure to rise, causing the intestinal canal and omentum to protrude outward through the defect in the left abdominal wall, forming an incarcerated hernia that cannot be returned and causing pain in the lower left abdomen. In this case, emergency surgery is needed to loosen the external ring opening and release the intestinal contents and omental compression to avoid intestinal necrosis if the condition is delayed for too long. Second, sigmoid torsion, mostly seen in young adults and elderly men. In young adults, it is mostly due to strenuous exercise after a full meal, and in the elderly, it is mostly due to a large amount of dry stool embedded in the sigmoid colon. Patients with sigmoid torsion may experience significant tenderness in the left lower abdomen, along with nausea, vomiting, and other signs of intestinal obstruction. In this case, if the manual repositioning fails, surgery is needed to release the torsion as soon as possible.