Interstitial cystitis and endometriosis can cause similar symptoms, like chronic pelvic pain, lower back pain, and pain during sex.

Interstitial cystitis is a painful disorder affecting your bladder. It can affect anyone, regardless of their sex. Endometriosis is another painful disease affecting the pelvis, though it typically only affects people with female reproductive organs.

This article will explore the link between interstitial cystitis and endometriosis. It will help you understand both conditions and explain their symptoms and treatment options.

How to tell them apart:

  • Endometriosis: Pain or other symptoms that tend to get worse before your period and improve afterward are more likely to be endometriosis or another hormone-related issue, like dysmenorrhea.
  • Interstitial cystitis: Pain that often happens with a full bladder or that improves after urination is more likely to be interstitial cystitis.

Interstitial cystitis, also called bladder pain syndrome, is a disorder characterized by irritation and inflammation of your bladder walls. The condition can lead to stiffening and scarring in your bladder.

If you have interstitial cystitis, you may experience:

  • pain in your pelvis or lower abdomen that gets worse during your period
  • an urgent need to pee
  • peeing more often than usual (up to 60 times a day)
  • pain when your bladder fills up that goes away after urination
  • pain during or after sex
  • a feeling of discomfort or pressure in your pelvic area, particularly around your bladder

The symptoms of interstitial cystitis can range from mild to severe. They may be persistent or come and go, with symptoms sometimes improving for days, weeks, or months at a time.

Endometriosis is a condition that occurs when tissue similar to the tissue that lines your uterus — which is known as the endometrium — grows outside of your uterus. These endometrial growths are typically found within pelvic structures such as your ovaries, bladder, bowel, and pelvic lining.

Endometriosis lesions expand during your period, which means symptoms like pain and cramping typically get worse around this time. But the symptoms of endometriosis can occur at any point during the month.

Common symptoms of endometriosis include:

  • severe pain during menstruation
  • heavy menstrual bleeding
  • pain during sex
  • abdominal and pelvic cramps
  • lower back pain
  • fatigue
  • fertility issues
  • pain or discomfort when pooping

Interstitial cystitis shares similar symptoms with endometriosis — especially a type of endometriosis called bladder endometriosis, which occurs in your bladder. Their overlapping symptoms can make it hard to tell which of them you have, so it’s best to consult with a doctor.

It’s also possible to have both conditions. In fact, people with endometriosis may be at an increased risk of developing interstitial cystitis.

One 2018 population-based study followed more than 9,000 people with endometriosis and more than 27,000 people without endometriosis over the course of 3 years. Researchers found that people with endometriosis were more than four times as likely to develop interstitial cystitis than people without endometriosis.

More studies need to be conducted to learn about the relationship between these conditions and why people with endometriosis appear to be at higher risk.

Diagnosing endometriosis and interstitial cystitis is tricky. There are no easy tests to reveal the presence of either of these conditions. Instead, a doctor will gather information from a variety of sources to help them narrow in on a diagnosis.

To find out whether you have interstitial cystitis or endometriosis, you may have the following tests:

Physical examination

A doctor will start by taking your medical history and asking questions about your symptoms. They may ask you how often you experience the symptoms, when they typically occur, and if you’ve noticed any possible triggers.

They may feel around your abdomen for inflammation or other irregularities. Depending on what type of doctor you see, they may also conduct an internal pelvic exam.

Tests to rule out other medical conditions

A doctor may recommend different tests, including a urinalysis and pelvic exam, to rule out other conditions that can cause similar symptoms, such as bladder inflammation, a urinary tract infection, or another gynecological condition.

Imaging tests

Imaging tests such as MRI and transvaginal ultrasound are also sometimes used to help diagnose endometriosis and interstitial cystitis. These tests use high frequency sound waves and magnetic waves to create detailed images of your pelvic area.

Laparoscopy and biopsy

Laparoscopy is the gold-standard diagnostic test for endometriosis. During this minimally invasive procedure, doctors make an incision in your abdomen and insert a laparoscope, which is a slender tube with a light and a camera.

They use this and other surgical tools to look around the inside of your pelvic cavity for signs of endometriosis. They can also collect tissue samples (biopsy) and send them to the lab for further examination.

Cystoscopy

During a cystoscopy, a doctor will use a device with a thin camera called a cystoscope to examine the inside of your bladder and your urethra, the tube that carries urine out of your body. This test helps diagnose interstitial cystitis and can be combined with a biopsy to help doctors get a clearer picture of what’s going on.

Your treatment will often depend on your symptoms. No single treatment works for everyone, and your treatment approach may differ depending on whether you have one or both conditions.

Treatment for endometriosis may include:

  • the use of pain relief medications such as naproxen and ibuprofen
  • hormonal medications like birth control pills and gonadotropin-releasing hormone (GnRH) analogues
  • fertility treatments if you’re trying to get pregnant
  • surgery to remove the endometriosis
  • dietary changes and exercise
  • relaxation techniques

A doctor may prescribe or suggest the following for interstitial cystitis:

  • physical therapy to relieve pelvic pain
  • medications for pain and inflammation, like nonsteroidal anti-inflammatory drugs (NSAIDs)
  • antihistamines
  • pentosan polysulfate sodium (Elmiron) for urinary frequency and bladder wall irritation
  • stimulating your sacral nerves to reduce how frequently and urgently you urinate
  • using mild electrical pulses in a process called transcutaneous electrical nerve stimulation (TENS) to reduce pelvic pain and reduce urinary frequency
  • placing medications such as dimethyl sulfoxide (Rimso-50) into your bladder
  • surgery to remove your bladder or make it larger

Endometriosis and interstitial cystitis both affect structures in your pelvis and can cause overlapping symptoms. Health experts are unsure what causes both conditions, but research suggests they’re linked.

If suspected, a doctor can run a series of tests to determine if you have one or both conditions. They’ll also recommend treatment options to help manage your symptoms.