Ganglion Impar Block

For people experiencing chronic pelvic, groin, or rectal pain, the most elemental tasks of daily life can become excruciating obstacles. This pain can be complex and difficult to resolve with systemic treatments or typical epidural injections. A ganglion impar block is a good option for people seeking relief from chronic pelvic, groin, or rectal pain. Here’s what you should know.

What is a ganglion impar block?

Understanding a ganglion impar block starts with a basic understanding of the anatomy of your pelvic bowl.

The ganglion is an area where multiple nerves come together. These nerves send all kinds of signals to the brain, including pain signals and other sensory information. The ganglion impar sits in front of the sacrum, the bony triangle located at the base of your spine.

Nerves in the ganglion impar control functions and response in the:

  • Anal area
  • Lower part of the urethra
  • Vagina and vulva
  • Scrotum
  • Tailbone
  • Lower area of the rectum

When chronic pain exists in any of these areas, a ganglion impar block can help. This type of block uses a local anesthetic for pain and a steroid for inflammation injected into the ganglion impar to disrupt pain signals.

Your doctor can also use a ganglion impar block diagnostically as well. If the cause or exact location of your pelvic pain has not yet been diagnosed, a successful ganglion impar block can help pinpoint the source of pain as occurring in this area.

How can a ganglion impar block help me?

Pelvic and groin pain can occur for a variety of reasons. The most common causes of this type of pain include:

  • Cancer in the vagina or vulva
  • Rectal or anal cancer
  • Cancer in the scrotum
  • Tailbone pain
  • Pain in the rectum

Although ganglion impar blocks are frequently used for disease in the pelvic and groin area, injury or trauma to this part of the body can also be treated with a ganglion impar block. For example, car accidents and sports injuries may result in pain in the lower body. A ganglion impar block can help provide relief.

Ganglion impar blocks have also provided relief for one of the 21st century’s “sitting diseases”: coccydynia. Coccydynia is pain that is caused by improper or excessive sitting postures. It can also occur when a person stands incorrectly for an extended period of time. This causes pain in the tailbone that usually responds to conservative treatments. When it does not, a ganglion impar block can provide relief.

Research reviews of the effectiveness of ganglion impar block have shown that many patients experience near total long-term pain relief. But these results depend on the individual patient, their overall health, and their underlying condition. The benefits of a ganglion impar block can be temporary for some people, and the amount and duration of pain relief varies from person to person. Some have relief for weeks; others benefit from the block for years.

Fortunately, the procedure is a low-risk, non-surgical treatment that if successful the first time will most likely continue to provide pain relief with repeat treatments.

An overview of the ganglion impar block procedure

This procedure usually takes less than 15 minutes and is generally completed under light sedation. This means you will remain awake during the procedure. All of your vital signs are monitored during the procedure. You may also receive supplemental oxygen through a nasal tube during the procedure.

Once you are relaxed and comfortable face-down on the examination table, your doctor will clean and sterilize the injection site. An injection of local anesthetic is given to make the procedure completely pain-free. This may sting briefly but will quickly become numb.

Your doctor will then insert a needle into the area around your tailbone. To ensure proper placement and limit the risk of damage to the surrounding tissues, they typically use fluoroscopic (X-ray) guidance. As the needle advances into the correct space, your doctor will stop when it reaches the ganglion impar—the injection target. A small amount of contrast dye is injected first. This dye shows up on an X-ray and is another way to make sure the injection is in the right spot.

Finally, your doctor will inject medication into the ganglion impar. This medication may include an anesthetic and a steroid, or it may just be one or the other. It depends on your condition. You may feel a warmth or a burning sensation at the injection site.

After the ganglion impar block procedure, you will rest for 30 minutes to an hour while your vital signs (heart rate, blood pressure, and oxygen level) are monitored. This is an outpatient procedure, and you will be released to go home shortly after it’s completed.

Side effects

The risks for this procedure are very low, but as with all medical procedures it’s important to understand all potential complications.

Potential risks include:

  • Bleeding from a misplaced injection
  • Nerve injury or paralysis
  • Puncture of surrounding organs (including rectum)
  • Puncture of nearby vessels

Drug allergy and seizure (if the medication is injected into a blood vessel) are possible but rare, as is the risk of infection.

In some cases, patients will find no pain relief. If this occurs, your doctor may try the injection from another approach.


Because you will receive light sedation for this procedure, ask a friend or family member to drive you home afterwards. Take it easy on the day of your procedure. Avoid strenuous exercise or activity for at least 24 hours.

Check with your doctor for specific recovery instructions. In general, keep these things in mind as you heal from your ganglion impar block.

  • It’s normal to have some pain at the injection site after the procedure. This should gradually decrease over a few days. Icing the injection site can offer comfort if you are sore.
  • Do not swim or soak in a bathtub until the injection site heals.
  • You can eat and drink normally directly after the procedure.
  • You can resume taking most medications after the ganglion impar block procedure but check in with your doctor to be sure.

As noted above, side effects are rare. Serious ganglion impar block side effects are rarer still. Contact your doctor immediately if you experience any of the following in the days after your block:

  • Severe pain
  • Weakness or numbness in the legs
  • Changes in bowel or bladder function
  • Fever
  • Redness, swelling, and oozing at the injection site


If you’re suffering from Pelvic Pain contact us today to see what Regen Doctors can do for you.