How is endometriosis diagnosed?

Although your provider may suspect endometriosis, surgery is required to confirm diagnosis. The gold standard for diagnosis is a biopsy (cutting out the suspicious tissue during surgery) and confirmation by pathologist (a specialized physician the removed tissue under microscope).
It is important that a surgeon experienced in identifying endometriosis perform the surgery to reduce the possibility of missing the diagnosis. Other tests, such as ultrasounds and magnetic resonance imaging, can help identify other problems or help the surgeon to prepare for surgery, but they are not used to diagnose endometriosis. “It is quite difficult to identify superficial diseases, peritoneal lesions, or early/mild deep endometriosis by imaging modalities (17,18), indicating that a negative diagnosis cannot rule out endometriosis” (Imanaka et al., 2020, para. 8).
It is also important that your provider is able to evaluate you for other conditions that may be contributing to your symptoms. Often individuals with endometriosis have other conditions that also need to be addressed. (see “Related Conditions”) These include but are not limited to:

  • Pelvic floor muscle pain
  • Adenomyosis
  • Interstitial cystitis/bladder pain syndrome



Imanaka, S., Maruyama, S., Kimura, M., Nagayasu, M., & Kobayashi, H. (2020). Towards an understanding of the molecular mechanisms of endometriosis-associated symptoms. World Academy of Sciences Journal2(4), 1-1. Retrieved from

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While a working diagnosis of endometriosis might be made from symptoms or other tests, a definitive diagnosis is only made by surgery with biopsy. It is important for your surgeon to have knowledge about all the different appearances of endometriosis as well as all the different areas it can be found

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Magnetic Resonance Imaging (MRI’s) and endometriosis

Surgery is the only method for definitive diagnosis of endometriosis; however, magnetic resonance imaging (MRI’s) can be used for preoperative planning as well as ruling out other related conditions. It is important to have a team who knows the correct protocol for imaging and for reading the images.

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Labwork and Blood Tests

While several companies are working to develop one, there is no single blood test that can definitively diagnose endometriosis yet. It takes a long time to determine if a test has the reliability “so that no patients with actual endometriosis would be missed and no women without endometriosis would be selected for potentially unnecessary additional procedures

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But your tests are all negative?

So often we get questions in our Facebook group about diagnostic studies for endometriosis. Patients are told repeatedly, your MRI/CT Scan/US/colonoscopy showed nothing, so you are disease free. This makes the path to diagnosis long and difficult for the patient. Since classic endometriosis symptoms are so pervasive and painful, these women persist in seeking answers. Still, on average, it takes 9 years to get a diagnosis.

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