Gram Stain of Urethral Discharge

Gram Stain of Urethral Discharge


  1. A gram stain of urethral discharge test is used to check for bacteria in your urethra, the tube that carries urine from your bladder to the outside of your body.
  2. To perform this test, your doctor will collect a sample of fluid from your urethra (using a sterile Q-tip), wipe it on a glass slide, add a drop of stain, and check for bacteria under a microscope.
  3. The test can help your doctor diagnose a sexually transmitted infection or bladder infection cause by bacteria. However, it can’t reveal the presence of viruses or fungi.

A gram stain of urethral discharge test is used to check for the presence of bacteria in your urethra. Your urethra is the canal that carries urine from your bladder to the outside of your body.

This test is particularly helpful for diagnosing sexually transmitted infections (STIs) and other bacteria that may infect your bladder. Your doctor may offer this test when you display symptoms of an infection. It will be performed by your doctor as an outpatient procedure.

What Symptoms Might Call for This Test?

Depending on your infection, several symptoms may occur. The most common are:

  • low urine output
  • burning during urination
  • abnormal vaginal or penile discharge, which may be foul-smelling or yellow, grey, or green in color
  • lesions on your genitals
  • swollen lymph nodes in your pelvic region
  • pain during sexual intercourse

Lesions that appear on the outside of your genitals, or inside your urethra or genitals, may cause significant discomfort during urination or sexual intercourse.

Medical conditions that are often responsible for these symptoms include:

  • gonorrhea
  • chlamydia STI
  • bladder infection
  • kidney infection
  • bacterial vaginosis
  • yeast infection
  • genital herpes

How Is the Test Performed?

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 your urethra using a cotton swab. The swab is then wiped over a glass slide, allowing your 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.

Diagnosing the Cause

Your doctor may be able to tell which bacteria are causing your infection based on what they see on the slide. Depending on the pathogen involved, a normal reading may vary. An abnormal reading can confirm the presence of a sexually transmitted infection or a bladder infection.

The gram stain can help your doctor diagnose a bacterial infection. A viral or fungal infection will not be revealed by this test.

Other tests may be needed depending on your gram stain reading.

Tests that are often ordered include:

  • vaginal culture
  • penile culture
  • Pap smear
  • urinalysis
  • blood test
  • culture sample taken from any visible lesions

What Treatment Options Are Available?

The results of your test will determine if treatment is necessary. In most cases, bacterial infections will require the use of prescription antibiotics. Depending on your type of bacterial infection, 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, aren’t treatable using antibiotics. You may be given a combination of antiviral medications and pain relief medications to treat a viral infection.

You doctor may discuss other treatment options with you.

What Are the Complications of This Test?

There aren’t any risks associated with a gram stain of urethral discharge. 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 your urethra or genitals. This may be a sign of a secondary infection or a flare-up from a viral infection, such as herpes.

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