This is the second blog post in a deep-dive series on endometriosis. In this post, we explore endometriosis’ symptoms and signs, and how to make a diagnosis of endometriosis.

Please read the first blog post in this series for background information regarding the causes, risk factors, and staging of endometriosis.

What symptoms can endometriosis cause?

The most common symptoms of endometriosis include:

Period pain

Endometriosis is a very common cause of moderate to severe period pain. (Please see this blog for a discussion about problematic period pain, and when to seek advice from your GP.)

If you have endometriotic nodules that have implanted in and around your pelvic organs, they can cause local inflammation when you have your period, and associated pelvic pain. Often described as severe cramps, these tend to occur in the middle of your tummy, below your belly button.

Chronic pelvic pain

Endometriosis is known to cause inflammation and internal scarring, which can cause your pelvic organs (e.g. uterus, ovaries, bowel) to stick together like glue. This internal scarring (or ‘adhesions’) can lead to pelvic pain, even when you don’t have your period.

In addition, endometriosis can lead to the pelvic nerves becoming overly-sensitive, and firing off pain signals to the brain, in a process called ‘central sensitisation’. This can lead to chronic pelvic pain – pain which lasts for more than six months.

Painful penetrative sex

Women with endometriosis often report that penetrative sex causes a deep, internal pelvic pain. Some sexual positions may be better than others.

Bowel symptoms

If an endometriotic nodule is growing close to or onto the bowel (often the rectum), it can lead to symptoms such as:

  • Blood mixed in with your poo during your period
  • Severe pain when opening your bowels during your period

If you have any of these symptoms, your GP or gynaecologist can request for a ‘deeply infiltrative endometriosis’ transvaginal ultrasound to be performed at a specialised ultrasound centre, which can help to diagnose bowel endometriosis. In order to see the bowel walls clearly, you made need to have a solution called “bowel prep” to empty the lower part of the bowel/rectum before your scan.

Bladder symptoms

If an endometriotic nodule has implanted onto the bladder, it can lead to the following symptoms:

  • Blood in your urine during your period
  • Pain with a full bladder during your period


There are several mechanisms by which endometriosis can impact upon a woman’s fertility. For example:

  • Endometriosis-related internal scarring can distort the anatomy of the pelvis, by sticking the organs together. This can distort (and even block) the Fallopian tubes, such that eggs released from the ovary during ovulation every month aren’t able to make their way down to the uterine cavity. If severe, this can make it difficult (if not impossible) to fall pregnant naturally.
  • There is some evidence that the presence of any endometriosis in the pelvis (even if it doesn’t block the Fallopian tubes) can create a toxic environment within the pelvis. This can make it difficult for an embryo to implant and grow inside the uterus.
  • Large endometriotic cysts on the ovaries (called ‘endometrioma’) can impair ovarian function, and interfere with ovarian reserve and ovulation.

What signs can endometriosis cause?

While symptoms are experienced by patients, ‘signs’ are those seen or felt by your doctor when they examine you.

Possible findings on bimanual examination

Your gynaecologist think that an internal examination is worthwhile. If so, they will seek your consent, and will perform a gentle internal examination, in order to determine where your pain is and what might be causing it. You can ask them to stop at any time.

They will be checking:

  • Your vulva for “vulvodynia”, which is burning of the skin of the vulva caused by nerve pain
  • Your pelvic floor muscles to see if there is any tenderness or tension.
  • Whether or not there is any: thickening of the uterosacral ligaments at the back of the vagina (a common place for endometriotic deposits); pain or tenderness of the ovaries on either side; and the uterus for pain or increased size.

Other possible signs

There are other less common signs of endometriosis, which include

  • Seeing vaginal endometriotic nodule on speculum examination
  • Discolouration on your abdomen, due to using a heat pack so often

How is endometriosis diagnosed?

‘Possible’ endometriosis based on your symptoms

Strictly speaking, the only way to diagnose endometriosis definitively is to undergo keyhole (‘laparoscopic’) surgery. However, if you have symptoms or signs (such as the above) that are very suggestive of endometriosis, it may be described that you have ‘possible’ or ‘suspected’ endometriosis. Your clinician may suggest medical management (see our next blog post for information about your options).

If medications control your symptoms, you may not feel the need to undergo keyhole surgery just to confirm definitively that you do or don’t actually have endometriosis.

The role of ultrasound in diagnosing endometriosis

High quality ultrasound (especially a ‘deeply infiltrative endometriosis’, or DIE transvaginal scan) is very good at diagnosing moderate (stage III) and severe (stage IV) endometriosis. (Please read this blog post for explanations of endometriosis staging.)

If bowel endometriosis is suspected, you may be required to have a solution to empty your bowels prior to this scan, so that the walls of the bowel can be seen clearly.

A good quality scan may find:

  • Endometriotic cysts on your ovaries (called an ‘endometrioma’)
  • Large nodules and related scarring in places where endometriosis often implants (e.g. the utero-sacral ligaments – the ligaments at the back of the vagina)
  • That your pelvic organs are all stuck together like glue, rather than gliding freely next to each other

These are all signs of likely moderate to severe endometriosis. If these are found on ultrasound, it may be said that you have ‘likely’ or ‘probable’ endometriosis.

The role of MRI in diagnosing endometriosis

Pelvic MRI has also been shown to be helpful in diagnosing deep infiltrating endometriosis, in particular bowel or extra-pelvic endometriosis (eg. up under your diaphragm). Your gynaecologist may suggest an MRI if:

  • You do not have easy geographic access to a specialised DIE ultrasound scan
  • You would rather not have a transvaginal ultrasound, due to pain or not having had penetrative vaginal sex previously
  • Or there is a high suspicion of bowel or other endometriosis which is harder to see on an ultrasound

Pelvic MRI is particularly helpful is revealing the location and depth of bowel nodules, which can help guide surgical management.

The role of keyhole (laparosopic) surgery in diagnosing endometriosis

Keyhole surgery is only way to definitively diagnose endometriosis. An advanced laparoscopic gynaecologist (such as Maven Centre’s Dr Sneha Parghi or Alison Bryant-Smith) can perform keyhole surgery through small incisions in your tummy, to look for and cut out any endometriotic nodules. These will then be sent off to the laboratory, where the specimens can be examined under the microscope, to confirm that it definitely is endometriosis.

Topic area frequently asked questions (FAQs)

Can I have keyhole surgery just to find out whether or not I have endometriosis?

Given the advancement of specialised ultrasound and MRI, gynaecologists are doing fewer  purely diagnostic laparoscopies. We should have a good idea based on your ultrasound (and/or MRI) prior to your operation whether your endometriosis is likely to minimal, mild, moderate or severe.

It’s important to note that a laparoscopy is still a surgery, and with all surgery comes risks. There is the risk of a general anaesthetic as well as the risks of laparoscopy, which includes damage to other organs in the abdomen (bowel, bladder, ureters, blood vessels), infection, and blood clots in the legs that can travel to the lungs.

If you have tried medical suppression (eg. the contraceptive pill) and it hasn’t provided sufficient symptomatic relief, or if you have sub-fertility but have a normal ultrasound, it is not unreasonable to have a laparoscopy to check whether or not your have endometriosis. No option will be off-the-table; this decision-making should be shared by you and your gynaecologist, to weigh up the risks and benefits of your options.

Does endometriosis always cause symptoms?

No. Endometriosis can sometimes be ‘asymptomatic’ which means without symptoms. Some people may describe significant period pain; some women have pain-free periods, and have no idea they have endometriosis. (In these cases, endometriosis may be discovered when undergoing an ultrasound to investigate something else, or during the journey of investigating infertility.)

I have severe period pain. Does that mean that I have severe endometriosis?

Unfortunately the correlation with pain and endometriosis isn’t so simple. While some women with extensive endometriosis can have minimal period pain, other women with severe period pain can have no visible endometriosis on laparoscopy.

If you suffer from significant period pain, it is worth going through the process of investigating for possible endometriosis. But it’s important to keep in mind that pain is complex, and many different causes can come together to create your pain experience. Your gynaecologist should discuss not  only the possibility of endometriosis, but also other causes of pelvic pain (and how to manage these).

Why are ‘DIE scans’ so expensive?

DIE scans are ultrasound scans performed by specialsed sonologists or sonographers who have done extra training in both gynaecological ultrasound, then even more training in how to look for endometriosis. They know where to look, and what to look for. Other ‘basic’ transvaginal ultrasound scans are often a simple review of the pelvic organs, without looking closely at the ligaments at the back of the vagina, or looking for signs of adhesions.

Given the need for these scans to be done by specially-trained operators, and the fact that they are longer and more detailed, DIE ultrasounds can be more expensive. However, the overall cost will be cheaper than needing multiple scans to get to the bottom of what is going on, a pelvic MRI or a laparoscopy.


Endometriosis is a complex condition, which can have significant and debilitating symptoms. Not all pain is endometriosis, and not all endometriosis causes pain! It is important to investigate the likelihood of you having endometriosis; this will inform your treatment options.

We look forward to collaborating with you to help you to be your best.