Urethral discharge culture is a laboratory test performed on men and boys to identify organisms in the urethra and genital tract that cause infection.

The opening of the urethra (at the tip of the penis) is cleansed with sterile gauze or cotton. A cotton swab is then gently inserted into the urethra about 3/4 inch and gently rotated. To ensure a good quality specimen, it should be collected at least 1 hour after urinating.

A culture of the discharge or exudate (the fluid that was collected) is then prepared in the laboratory. Any organisms that grow on the culture are isolated and identified. The drainage may be examined by gram stain on a slide under the microscope for preliminary results and confirmed by culture.

Do not urinate for 1 hour before the test. Urination will wash away some of the organisms needed to obtain an accurate culture.

There is usually some discomfort associated with swabbing the urethra.

Often the test is performed when there is a discharge from the urethra. This test can be performed to detect sexually transmitted diseases such as gonorrhea and chlamydia.

A negative culture, or no growth appearing in the culture, is normal.

Abnormal results can indicate infection within the genital system. These infections can include gonorrhea or chlamydia.

See also:

• Chlamydial urethritis, male
• Chronic urethritis
• Gonococcemia (disseminated)

Fainting (caused by stimulation of the vagal nerve) occasionally occurs when the swab is introduced into the urethra. Other risks include infection or bleeding.

A comparable test for women and girls is an endocervical culture.