A gram stain of urethral discharge test is used to check for the presence of bacteria in the urethra tube. The urethra tube is the canal that carries urine from the bladder to the outside of the body.
This test is particularly helpful in diagnosing sexually transmitted infections (STIs) and other bacterial or viral infections that affect the bladder. This test is often offered when a person displays symptoms of an infection. The gram stain of urethral discharge test is performed by your doctor as an outpatient procedure.
Depending on the infection present, several symptoms may occur. The most common are:
- burning during urination
- abnormal vaginal or penile discharge (foul-smelling or yellow, grey, or green)
- low urine output
- lesions on the genitals
- swollen lymph nodes in the pelvic region
- pain during sexual intercourse
Medical conditions that are often responsible for these symptoms include:
- bladder infection
- kidney infection
- bacterial vaginosis
- yeast infection
- genital herpes
The test is given in your doctor’s office. It may cause a slight burning or stinging sensation.
Your doctor will take a sample of the fluid from the urethra using a cotton swab. The swab is then wiped over a glass slide, allowing the doctor to view the contents under a microscope. The doctor applies stain to the sample. This is called a gram stain. Once the stain is applied, the doctor will view the specimen under a microscope for the presence of bacteria.
The doctor may be able to tell which bacteria are causing the infection based on how they appear on the slide. Depending on the bacteria discovered, a normal reading may vary. An abnormal reading can confirm the presence of a sexually transmitted infection or a bladder infection. The gram stain may be useful only if the infection is a result of a bacterial infection. A viral or fungal infection will not be revealed by this test.
Other tests may be needed depending on the gram stain reading.
Tests that are often ordered include:
- vaginal culture
- penile culture
- Pap smear
- blood test
- culture sample (taken from any visible lesion)
The results of the test will determine if treatment is necessary. In most cases, bacterial infections will require the use of prescription antibiotics. Depending on the type of bacterial infection present, you may receive an antibiotic. You may also be prescribed pain relief medications or directed to use over-the-counter pain relief medications.
Viral infections such as genital herpes are not treatable using antibiotics. You may be given a combination of antiviral medications and pain relief medications to treat this condition. Lesions that appear on the outside of the genitals as well as within the urethra or genitals may cause significant discomfort during urination.
Other treatment options will be discussed by your doctor.
There aren’t any risks associated with this examination. However, complications may arise from an abnormal test reading. Some infections cause a risk of scarring or impaired fertility if they aren’t diagnosed and treated promptly.
Call your doctor if you feel pain, discomfort, or experience a resurgence of abnormal discharge from the urethra or genitals. This may be a sign of a secondary infection or a flare-up from a viral infection such as herpes.