There are more causes of left abdominal distension in men, and the common causes include the following: the first one, left spermatic varicose vein, some left spermatic varicose vein patients have left abdominal distension after standing for a long time. The second, the left ureteral stones, if the left ureteral stones caused by the left hydronephrosis, will also appear the left abdominal distension and discomfort. The third, due to intestinal disease, especially sigmoid disease, will also appear left abdominal distension and discomfort. The fourth, some patients with prostatitis will also have left abdominal distension and discomfort. The fifth, stomach disease or pancreatic cysts can also cause distension and discomfort in the upper left abdomen. So there are more reasons for men to have left abdominal distension and they need to go to the hospital to further check the causes of left abdominal distension.