The bulbourethral gland is a small gland approximately the size of a pea that is part of the male reproductive system. Two bulbourethral glands are attached to the urethra and are located behind it with one on each side. Also known as Cowper’s gland in honor of the English surgeon and anatomist William Cowper who provided early descriptions of it, the bulbourethral gland is an exocrine gland. The secretions of exocrine glands are ultimately transported out of the body. In the case of the bulbourethral gland, such secretions leave the body through the urethra.
A clear, colorless, and somewhat viscous component of pre-ejaculatory fluid, known as Cowper’s fluid, is discharged by the bulbourethral gland into the urethra when the male becomes sexually aroused. It is then secreted out of the body through the urethra before ejaculation. While Cowper’s fluid itself does not contain semen, semen may be present in pre-ejaculatory fluid from other sources such as residual sperm from a previous ejaculation. Therefore, it is commonly recommended by medical professionals to avoid using withdrawal as a method of pregnancy prevention even if withdrawal is completed before ejaculation.
Discharge of Cowper’s fluid by the bulbourethral gland helps to flush any debris out of the urethra before sexual intercourse. Its relative alkalinity helps neutralize any residual acidity in the urethra from urine and the naturally acidic environment of the vagina. This helps create a more hospitable environment conducive to the survival of sperm that increases the chance of reproduction. Cowper’s fluid contributes to lubrication of both the penis and the vagina during sexual activity. It also plays a role in the coagulation of semen a few seconds after ejaculation from the penis.
Little is known about disorders of the bulbourethral gland. Among the most commonly experienced problems are Cowper’s duct cysts. While Cowper’s duct cysts are fairly rare, they are more common among adolescent males than adults. They are considered relatively benign urological abnormalities, but they may cause such symptoms as reduced urinary flow and bloody discharge from the urethra. Surgical procedures may be prescribed to provide relief of these symptoms.
High volume of pre-ejaculatory fluid is not typically considered a medical disorder as the amount of such fluid varies widely from individual to individual. Some males, particularly adolescent and young adult males and those not regularly engaging in sexual activity, may find the amount of fluid produced to be inconvenient and sometimes embarrassing. Medical treatment is not typically prescribed for this condition, but hormone therapy may be prescribed in the most extreme cases.