Endometriosis is often talked about by IC patients, because the two conditions co-exist in a lot of IC patients. A study in 2007 reported that 66 percent of patients had both IC and endometriosis while endometriosis.org puts that number higher at 80 to 90 percent.(1)(2) No matter which figures are correct, the connection between the two conditions is certainly apparent.

Though endometriosis is best known for its impact on the uterus, its lesser known counterpart, bladder endometriosis, invade the bladder and, more rarely, the urinary tract. With symptoms very similar to IC, bladder endometriosis can be missed in IC patients, which is challenging since it has a whole other line of treatment.

What is endometriosis?

Endometriosis occurs when cells from the lining of the uterus invade other parts and organs.(3) The cells attach themselves to those areas and then proceed to perform their monthly, hormone-induced function of building up then breaking down and bleeding. However, unlike in the uterus, the blood has nowhere to go and causes painful inflammation and scar tissue.(3)

Symptoms of endometriosis include the following:

  • periods that are heavy, painful and/or irregular
  • pain with or after intercourse
  • pain with bowel movements
  • fertility problems
  • fatigue

A study in 2018 found that patients who have endometriosis are four times more likely to develop IC as well.(4)

What is bladder endometriosis?

Bladder endometriosis is one type of endometriosis. It is a rare form of the disease, but it happens when cells from the uterus attach themselves to the bladder. If the cells attach only to the bladder surface, it is called superficial endometriosis; if the cells are embedded into the bladder lining or wall, it is called deep endometriosis.(5)

A study in 2004 estimated that 1 to 5 percent of endometriosis patients have endometriosis in their urinary system, with the vast majority of those patients having it in their bladder.(6) Different researchers stated in a 2018 study that urinary endometriosis occurs in only 1 percent of endometriosis patients, again with the vast majority occurring in the bladder.(7) No matter how you look at it, the number of patients who develop urinary endometriosis is pretty small. But for those patients and their doctors, knowing what is going on in their bodies and how to best treat it is important.

What are the symptoms of bladder endometriosis?

The symptoms of bladder endometriosis are very similar to IC. They include the following:

  • urgency
  • frequency
  • pain when the bladder is full
  • burning/pain with urination
  • blood in the urine
  • pain in the pelvis
  • pain on one side of the lower back

These symptoms usually appear or at least worsen during periods.(5) However, a study review in 2012 found that 30 percent of women with bladder endometriosis have no symptoms.(8) Typically those women had incidences of lesions no more than 2 cm in diameter.(8)

How is bladder endometriosis diagnosed?

The first step toward diagnosis is usually a physical examination of the vagina and bladder. A urinalysis looking for blood in the urine is also common. If bladder endometriosis is suspected then further testing occurs.(5)

One of the least invasive ways to identify bladder endometriosis is through an ultrasound of the bladder.(5) MRI scans and cystoscopies (a camera inserted into the bladder) can also find bladder endometriosis and which of the four stages it is in. Having a biopsy with the cystoscopy is important to determine whether the tissue is from endometriosis or IC since the treatments are so different.(9) Endometriosis is categorized based on how much tissue is present and how far it goes into organs. The stages are minimal, mild, moderate and severe.(5)

How is bladder endometriosis treated?

There are two main options for treating bladder endometriosis, which are pretty much the same as treating any endometriosis: medication and surgery.

Hormone-regulating medicines can help ease the symptoms of bladder endometriosis and slow its growth.(5)

Surgery to remove the endometrial tissue is the more definitive way to treat bladder endometriosis. Often, though, the tissue is in the full thickness of the bladder wall so removing a portion of the bladder is common.(9) However, removing the tissue surgery isn’t a guarantee it will stay gone. A study in 2006 found that three years post-op, 16 to 25 percent of patients had a return of bladder endometriosis.(10)

Treatment is important, though, because bladder endometriosis left unchecked and untreated can result in kidney damage.(5)



  1. Paulson JD, et. al. The Relationship Between Interstitial Cystitis and Endometriosis in Patients With Chronic Pelvic Pain. JSLS. April-June 2007 Volume 11, No. 2.
  2. Dulemba J. Interstitial cystitis. Endometriosis.org.
  3. Bladder and Bowel Community. Endometriosis Symptoms and Treatments.
  4. Chia-Chang W, et. al. Endometriosis Increased the Risk of Bladder Pain Syndrome/Interstitial Cystitis: A Population‐Based Study. Neurourology and Urodynamics. April 2018 Volume 37, No. 4.
  5. Watson S. What is Bladder Endometriosis? Healthline.com. Oct. 18, 2017.
  6. Pastor JF, et. al. Bladder Endometriosis and Endocervicosis: Presentation of 2 Cases with Endoscopic Management and Review of Literature. Case Report in Urology. Volume 2014.
  7. Fernandes RP, et. al. Standard Approach to Urinary Bladder Endometriosis. J Minim Invasive Gynecol. Sept.-Oct. 2018, Volume 25, No. 6.
  8. Maccagnano C, et. al. Diagnosis and Treatment of Bladder Endometriosis: State of the Art. Urol Int 2012 Volume 89, No. 3.
  9. Center for Special Minimally Invasive & Robotic Surgery. Bladder Endometriosis.
  10. Beaty SD, et. al. Bladder Endometriosis: Ultrasound and MRI Findings. Radiol Case Rep. 2006 Volume 1, No. 3.