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, women waited a median of eight years from the start of their symptoms to a diagnosis. Pain that disrupts your life is not something you simply have to accept.
Endometriosis takes several forms, and the distinction matters for 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.
- Womb
- Pelvic lining (peritoneum)
- On the bladder
- Bladder
- Cyst on the ovary (endometrioma)
- Bowel wall (deep endometriosis)
- Pouch of Douglas (behind the womb)
- Between vagina and bowel (deep nodule)
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.
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 (RCOG, 2022).
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.
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.
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.
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. 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 matters, 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 return to desk-based work within one to two weeks.
- Surgery for endometriomas: usually one night in hospital, with two to three weeks before returning to most activities.
- 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.