Endometriosis

Endometriosis in plain language

Endometriosis is a condition in which tissue similar to the lining of the womb (the endometrium) grows outside the womb, most often on the lining of the pelvis (the peritoneum), on the ovaries, and in the space behind the womb. Each month this tissue responds to the same hormones as the lining of the womb. It causes inflammation, and over time it can lead to scarring and to organs sticking together (adhesions).

It is common, affecting around one in ten women of reproductive age in the UK. Despite that, it often takes years to be recognised. In a study my colleagues and I published from a UK specialist centre, half the women waited eight years or more from the start of their symptoms to a diagnosis ^[1]. My article why endometriosis takes so long to diagnose explains what lies behind the delay and what can help. Pain that disrupts your life is not something you simply have to accept.

Endometriosis takes several forms, and the distinction affects treatment:

• Superficial endometriosis lies on the surface of the pelvic lining.
• Endometriomas are cysts on the ovary filled with old blood, sometimes called “chocolate cysts”.
• Deep endometriosis grows more than a few millimetres into the tissues and can involve the bowel, the bladder, the ureters (the tubes that carry urine from the kidneys) or the area between the vagina and the bowel.

Adenomyosis is a related condition in which similar tissue grows into the muscle wall of the womb itself. The two often occur together. The adenomyosis page explains it in detail.

Symptoms

Endometriosis affects women very differently, and the amount of disease does not always match the severity of the pain. Common symptoms include:

• periods that are painful enough to disrupt work, study or family life
• pelvic pain between periods, which may become constant
• pain during or after sex (deep dyspareunia)
• pain when opening the bowels or passing urine, especially around a period
• bleeding from the bowel or bladder around a period, which is less common
• difficulty conceiving
• tiredness and low mood, which often accompany long-standing pain

Some women have few symptoms and learn they have endometriosis during investigations for fertility.

How I assess endometriosis

At your first consultation I take a careful history, because the pattern of your symptoms tells me a great deal about where endometriosis may be. I will ask about your periods, your pain, your bowel and bladder, your plans for a family, and the treatments you have already tried. With your permission, I will examine you.

At Parkside Hospital and the CRP Clinic I can perform a transvaginal ultrasound scan during the consultation, so that we can usually discuss what it shows at the same visit. In experienced hands, ultrasound can show endometriomas, signs of deep endometriosis and the mobility of the organs in the pelvis. When deep disease is suspected I may arrange an MRI scan, reviewed with a specialist endometriosis radiologist, to map it before any operation.

A normal scan does not rule endometriosis out. Superficial disease is usually invisible on imaging, and a laparoscopy (a keyhole look inside the abdomen) remains the way to confirm it. You do not need a laparoscopy before starting treatment: pain relief and hormone treatment can begin while investigations continue.

Treatment options

There is no single right treatment for everyone. The right choice depends on your symptoms, the type and extent of disease, whether you hope to become pregnant and what matters most to you. I will explain every reasonable option, including the option of no treatment, give you my recommendation and leave the decision with you.

Without surgery

• Pain relief. Simple painkillers and anti-inflammatory medicines, taken regularly around a period, help many women.
• Hormonal treatment. Treatments that reduce or stop periods, such as the contraceptive pill, progestogen-only treatments or a hormonal coil, can control symptoms well for a large number of women. In some situations I may suggest medicines that temporarily switch off the ovaries’ hormone production, usually with hormone replacement to protect the bones and reduce side effects. Hormonal treatment controls symptoms while you take it; it does not remove endometriosis, and it is not suitable while trying to conceive.
• Support beyond medication. Pelvic physiotherapy, specialist pain services and the patient support offered by Endometriosis UK can all make a real difference, particularly when pain has been present for a long time.

Supplements

Many women ask whether supplements can help. A 2026 review brought together 24 randomised trials involving about 2,000 women with endometriosis ^[13]. Some small trials found less pain with a specially absorbed form of curcumin (the active part of turmeric), with selenium taken alongside hormone treatment, or with garlic. Results for vitamins and melatonin were mixed, and fish oils, ordinary curcumin and resveratrol showed no clear benefit. None of them improved the chance of pregnancy or stopped endometriosis coming back after surgery.

Because the trials were small and each tested a different product, no supplement can yet be recommended as a treatment in its own right. If you would like to try one alongside your treatment, we can talk it through, but it should not replace a treatment that is working for you.

Surgery

Surgery is worth considering when symptoms continue despite medical treatment, when a scan shows deep disease or an endometrioma, or when endometriosis may be affecting your fertility. I carry out almost all endometriosis surgery by keyhole surgery, either laparoscopic or robotic (da Vinci). Both are forms of keyhole surgery performed through small incisions, which for most women means less pain and a quicker recovery than open surgery.

For deep endometriosis my preferred approach is robotic surgery. The Royal College of Obstetricians and Gynaecologists describes it as a tool that may allow surgeons to remove deep endometriosis more easily and safely, and found the evidence so far shows it to be at least as good as conventional keyhole surgery, with a trend towards fewer complications ^[10].

Where it is safe to do so I remove endometriosis by excision, cutting it out rather than burning the surface. This removes the whole deposit and allows it to be confirmed under the microscope. Some studies suggest that excision relieves certain types of pain more effectively than ablation (destroying the surface), although the evidence is not conclusive.

In 2014 my colleagues and I received the Carlo Romanini Award of the American Association of Gynecologic Laparoscopists (AAGL) for the best abstract on endometriosis. It was awarded for our trial for superficial endometriosis comparing excision with the Harmonic scalpel (an ultrasonic cutting instrument) against carbon dioxide laser vaporisation (burning the tissue away with a laser). We presented the longer-term results in 2019: in the 116 women in the trial, pain scores were lower after excision than after vaporisation at one year and at three years ^[9].

For endometriomas, I usually remove the cyst wall while preserving as much healthy ovary as possible, which lowers the chance of the cyst coming back. The alternative is to drain the cyst and treat its lining (ablation). If you hope to become pregnant, we will choose between these together, taking into account your egg supply (ovarian reserve). For deep endometriosis, the operation is planned in detail beforehand from the scans.

A Finnish national study followed almost 14,000 women for about 20 years after an operation for an endometrioma: about one in six needed a further operation, more often among younger women and those with a family history of endometriosis, and the chance was higher when the ovary had been kept (about one in three) than when it had been removed (about one in ten), which is one of the things we weigh together against your ovarian reserve and your plans for a family ^[11].

Endometriosis is not cancer. Women with endometriomas or deep endometriosis do have a higher chance of ovarian cancer: nearly ten times the risk, although ovarian cancer remains uncommon, about 27 more women in every 10,000 ^[12].

For women who do not want a future pregnancy and whose symptoms are severe, a hysterectomy (removal of the womb), with or without removal of the ovaries, is sometimes the right choice, particularly when adenomyosis is also present. It is a significant decision, it is not a guaranteed cure, and I will discuss it with you over more than one conversation.

Deep endometriosis and the multidisciplinary team

Deep endometriosis affecting the bowel, bladder and ureters is a large part of my work. At the BSGE-accredited centre I lead, women with deep disease are cared for by a multidisciplinary team: gynaecologists, colorectal surgeons, a specialist endometriosis radiologist and specialist nurses. In my private practice I follow the same approach. When a case calls for it I operate alongside a colorectal surgeon, or a urologist when the bladder or ureters are involved, and the plan for your operation is agreed in advance.

Where endometriosis lies close to the ureters, I free them from the tissue around them first (ureterolysis), so that I can see them throughout the operation. I have published this approach for complex keyhole surgery ^[7], and endometriosis is one of the most common reasons I use it.

Depending on how deeply the bowel is involved, the endometriosis may be shaved from its surface, removed with a small disc of bowel wall, or removed with a short segment of bowel that is then rejoined. Very occasionally a temporary stoma (an opening of the bowel onto the abdomen) is needed to protect a join while it heals. Surgery for deep endometriosis is major surgery with real risks, which I will go through with you in detail, so that you can weigh them against the likely benefits.

A study our team published in 2016 followed women who had keyhole surgery for severe endometriosis affecting the bowel; at a year after surgery they reported significant improvements in pain, sexual function and quality of life ^[2].

Surgery helps most women with endometriosis, although not every woman. In one trial, women were chosen at random either to have their endometriosis removed or to have only a look inside. Six months later, eight in ten of the women who had it removed felt better, compared with about three in ten of those who did not ^[3].

Surgery can also help women who are trying to become pregnant. In women with mild endometriosis, removing it nearly doubled the chance of a pregnancy that continued past the halfway point, from about one in six to about one in three ^[4]. European guidance from ESHRE recommends surgery as one of the choices for endometriosis pain, and as an option for women with endometriosis who are finding it hard to conceive ^[5].

When endometriosis affects the bowel, our own research found that women who had less pain before surgery were less likely to notice an improvement afterwards ^[6]. This helps us decide together whether surgery is likely to help you. Results vary from one woman to another, and I will talk with you about what is realistic in your case.

Endometriosis and fertility

Endometriosis can make it harder to conceive, although many women with endometriosis become pregnant without help. Removing endometriosis can improve the chance of natural conception for some women. Surgery on the ovaries, however, can reduce the number of eggs they hold, so for women hoping to conceive I weigh this carefully, sometimes after a blood test of ovarian reserve (the anti-Müllerian hormone test).

As an honorary consultant at King’s Fertility, I am used to planning surgery around fertility treatment. Where IVF is likely to be needed, the order of treatment is important, and I will agree it with you and, where helpful, with your fertility clinic. You can read more on the fertility and miscarriage surgery page.

What surgery involves and recovery

Before any operation you will receive full written information about the procedure, its risks and the recovery to expect, well in advance. On the day, the operation is carried out under general anaesthetic through several small incisions, usually one in the navel and two or three lower down. I carry out the operation myself and see you afterwards to explain what I found.

• Laparoscopy for superficial endometriosis: most women go home the same day or the next morning, and I usually advise about four weeks before returning to work.
• Surgery for endometriomas: usually one night in hospital, and about four weeks before returning to work.

After either of these, if you work from home and need to, light desk work after about two weeks is often possible.

• Surgery for deep endometriosis: usually a few nights in hospital, particularly when the bowel or bladder is involved, and around four to six weeks or more before you feel back to normal.

All surgery carries risks, including bleeding, infection, injury to the bowel, bladder, ureters or blood vessels, and blood clots. Occasionally it is safer to convert a keyhole operation to an open one. I will explain how these risks apply to you. I see you again after surgery to go through the findings and the results from the laboratory, and to plan any further treatment.

Listen: endometriosis on The Fertility Suite podcast

I talked about endometriosis, and about Asherman’s syndrome, with Rachel Sherriff on The Fertility Suite podcast in February 2024: how endometriosis can affect fertility, the symptoms to look out for, how it is diagnosed and the treatment options. Listen to the episode.