Men’s abdominal distension, may be a physiological phenomenon, can be seen in men after sex prostate congestion, etc.; may also be caused by certain diseases, the most common is prostate hyperplasia, prostatitis, ureteral disease, sigmoid colon disease, should be timely medical examination to identify the cause of the disease. 1. Physiological phenomenon: When sex, the prostate will have congestion, so in the short term there will be swelling and pain symptoms, this is normal, usually after rest will be better. 2. Pathologic factors: (1) prostatic hyperplasia: especially in older men, prostatic hyperplasia and hypertrophy lead to bladder urination difficulties, the prostate gland compresses the surrounding tissues, and there is often a small abdominal distension and pain. (2) Prostatitis: acute bacterial prostatitis, mostly sudden onset, manifested as acute pain in the lower abdomen, accompanied by abnormal urination-related symptoms and fever. Chronic prostatitis (chronic pelvic pain syndrome), the clinical manifestations are more numerous and complex, mostly pelvic region (including the abdomen) pain, urinary frequency, urinary pain, abnormal urethral discharge, sexual dysfunction, mental and psychological disorders and other symptoms. (3) Ureteral stones and bladder stones: they can also cause distension and pain in the lower part of the abdomen, but are usually accompanied by symptoms of urinary frequency, urgency and pain. (4) Diseases caused by inflammatory polyps or tumors in the sigmoid colon or rectum: they can also cause pain in this area, but usually accompanied by diarrhea, blood in the stool and other symptoms. In summary, there are many other causes of bloating and pain in the lower abdomen. If you experience this symptom, you should go to the hospital in time to see a doctor to clarify the cause and then give targeted treatment.