This is a medical question of type : causes 
 What causes Perineal Injury in Males ? 
 Common causes of acute perineal injury in males include
                
- perineal surgery  - straddle injuries  - sexual abuse  - impalement
                
Perineal Surgery
                
Acute perineal injury may result from surgical procedures that require an incision in the perineum:
                
- A prostatectomy is the surgical removal of the prostate to treat prostate cancer. The prostate, a walnut-shaped gland in men, surrounds the urethra at the neck of the bladder and supplies fluid that goes into semen. The surgeon chooses the location for the incision based on the patients physical characteristics, such as size and weight, and the surgeons experience and preferences. In one approach, called the radical perineal prostatectomy, the surgeon makes an incision between the scrotum and the anus. In a retropubic prostatectomy, the surgeon makes the incision in the lower abdomen, just above the penis. Both approaches can damage blood vessels and nerves affecting sexual function and bladder control.  - Perineal urethroplasty is surgery to repair stricture, or narrowing, of the portion of the urethra that runs through the perineum. Without this procedure, some men would not be able to pass urine. However, the procedure does require an incision in the perineum, which can damage blood vessels or nerves.  - Colorectal or anal cancer surgery can injure the perineum by cutting through some of the muscle around the anus to remove a tumor. One approach to anal cancer surgery involves making incisions in the abdomen and the perineum.
                
Surgeons try to avoid procedures that damage a persons blood vessels, perineal nerves, and muscles. However, sometimes a perineal incision may achieve the best angle to remove a life-threatening cancer.
                
People should discuss the risks of any planned surgery with their health care provider so they can make an informed decision and understand what to expect after the operation.
                
Straddle Injuries
                
Straddle injuries result from falls onto objects such as metal bars, pipes, or wooden rails, where the persons legs are on either side of the object and the perineum strikes the object forcefully. These injuries include motorcycle and bike riding accidents, saddle horn injuries during horseback riding, falls on playground equipment such as monkey bars, and gymnastic accidents on an apparatus such as the parallel bars or pommel horse.
                
In rare situations, a blunt injury to the perineum may burst a blood vessel inside the erectile tissue of the penis, causing a persistent partial erection that can last for days to years. This condition is called high-flow priapism. If not treated, ED may result.
                
Sexual Abuse
                
Forceful and inappropriate sexual contact can result in perineal injury. When health care providers evaluate injuries in the genital area, they should consider the possibility of sexual abuse, even if the person or family members say the injury is the result of an accident such as a straddle injury. The law requires that health care providers report cases of sexual abuse that come to their attention. The person and family members should understand the health care provider may ask some uncomfortable questions about the circumstances of the injury.
                
Impalement
                
Impalement injuries may involve metal fence posts, rods, or weapons that pierce the perineum. Impalement is rare, although it may occur where moving equipment and pointed tools are in use, such as on farms or construction sites. Impalement can also occur as the result of a fall, such as from a tree or playground equipment, onto something sharp. Impalement injuries are most common in combat situations. If an impalement injury pierces the skin and muscles, the injured person needs immediate medical attention to minimize blood loss and repair the injury.