Definition

Urethral discharge culture is a laboratory test done on men and boys. This test is used to identify germs in the urethra that may be causing inflammation of the urethra (urethritis). The urethra is the tube that drains urine from the bladder.

Alternative Names

Culture of urethral discharge; Genital exudate culture; Culture - genital discharge or exudate; Urethritis - culture

How the Test is Performed

The health care provider uses sterile cotton or gauze to clean the opening of the urethra at the tip of the penis. To collect the sample, a cotton swab is then gently inserted about three-fourths inch (2 centimeters) into the urethra and turned. To get a good sample, the test should be done at least 2 hours after urinating.

The sample is sent to a lab. There, it is placed in a special dish (culture). It is then watched to see if bacteria or any other germs grow.

How to Prepare for the Test

DO NOT urinate for 1 hour before the test. Urinating washes away some of the germs needed for accurate test results.

How the Test will Feel

There is usually some discomfort from swabbing the urethra.

Why the Test is Performed

The provider often orders the test when there is a discharge from the urethra or other symptoms of infection. This test can detect sexually transmitted infections (STIs), such as gonorrhea and chlamydia.

Normal Results

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

What Abnormal Results Mean

Abnormal results can be a sign of infection in the genital tract. These infections can include gonorrhea or chlamydia.

Risks

Fainting may occur when the swab is introduced into the urethra. This is due to stimulation of the vagus nerve. Other risks include infection or bleeding.

References

Babu TM, Urban MA, Augenbraun MH. Urethritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 107.

Plourde AR, Beavis KG. Specimen collection and handling for diagnosis of infectious diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 66.