Rectovaginal endometriosis

Rectovaginal endometriosis occurs when tissue similar to the lining of your womb (endometrium) starts to grow elsewhere, specifically in your  back passage (rectum), vagina and structures between them. The tissue responds to hormonal changes during your menstrual cycle in the same way that endometrium tissue in your womb does. However, as it is outside your womb, it can cause inflammation, scarring and other problems with nearby organs. 

Rectovaginal endometriosis is one of the most severe types of endometriosis. In the four-stage classification system, it is classed as stage 4 endometriosis due to the large amount of endometrium tissue found outside the womb and the extent that it has spread. Rectovaginal endometriosis often causes gastrointestinal problems and chronic (long-term) pelvic pain and in some cases, leads to fertility problems.

What is rectovaginal endometriosis?

Rectovaginal endometriosis is a less common but severe type of endometriosis, where the endometrium tissue grows into your rectum, vagina and tissues in between them.

The patches of endometrium tissue (lesions) that grow outside of your womb in rectovaginal endometriosis can become quite large, causing pain and disrupting the function of nearby organs. These lesions can also lead to bleeding and infections.

Is rectovaginal endometriosis common?

Rectovaginal endometriosis is a less common type of endometriosis, affecting around a third of women with endometriosis. Most women with endometriosis, therefore, have ovarian endometriosis, where the endometrium tissue lines the ovaries, or peritoneal endometriosis, where the endometrium tissue lines the abdominal cavity.

Rectovaginal endometriosis symptoms

Symptoms of rectovaginal endometriosis include:

• Bladder pain, pelvic pain and/or severe cramps
• Bleeding in between your periods
• Heavy and/or painful periods
• Infertility and fertility problems — rectovaginal surgery and in vitro fertilisation (IVF) can improve fertility
• Pain during sex
• Urinary incontinence and/or bowel incontinence

Other symptoms of rectovaginal endometriosis include:

• Bleeding from your rectum — this may occur alongside menstrual bleeding
• Bloating and fluid retention
• Irritable bowel syndrome (IBS) symptoms eg constipation and diarrhoea
• Needing to strain to open your bowels and/or painful bowel movements
• Severe stomach pain
• Swelling of your rectum, stomach, vagina and/or the lining of your abdomen (peritoneum)

Symptoms often get worse during periods. However, some people with rectovaginal endometriosis may not experience any symptoms. The severity of your symptoms doesn’t necessarily suggest how extensive your rectovaginal endometriosis is ie you can experience chronic pain with mild endometriosis or mild discomfort with severe endometriosis.

Causes of rectovaginal endometriosis

The exact causes of rectovaginal endometriosis aren’t yet known, although genetics may play a role as it can run in families. If you have a mother or sister with endometriosis, your risk of developing it is two to 10 times greater than a woman who has no family history of the condition.

Inflammation may also increase your risk as tissues affected by endometriosis have high levels of inflammatory markers.

Pelvic surgery, such as a C-section or laparotomy, may increase your risk of endometriosis too.

Endometriosis that penetrates deep into tissues, which includes rectovaginal endometriosis, tends to first develop in women in their early twenties.

Other potential risk factors for developing endometriosis include:

• Autoimmune conditions — conditions that affect your immune system may prevent it from locating and removing endometrium tissue that grows outside of your womb, resulting in endometriosis
• Hormonal imbalances
• Retrograde menstrual flow — when your menstrual bleeding doesn’t all pass out of your vagina but flows backwards into your fallopian tubes
• Trauma to your womb or surrounding tissues — this can include surgery eg C-section

Rectovaginal endometriosis diagnosis

It can be difficult to diagnose endometriosis as symptoms vary and other conditions have similar symptoms. For some women without any symptoms, endometriosis may only be diagnosed as part of investigations into fertility problems.

If you do have symptoms of endometriosis, such as pelvic or abdominal pain, bloating, heavy and/or painful periods, or irregular vaginal bleeding, it is important to see your GP. They will ask you about your symptoms and your medical history. 

They may also perform a physical examination of your pelvis to check for pain, lumps or other unusual growths. To do this, they will insert a gloved, lubricated finger into your vagina and rectum.  

Further tests may be needed to make a diagnosis of endometriosis. Your doctor may therefore recommend you have an imaging test, such as:

• CT colonography, also known as a virtual colonoscopy — this uses  low-dose X-rays to create images of your colon and rectum and unlike a traditional colonoscopy, does not involve inserting any devices into your colon
• Ultrasound scan — this uses high-frequency sound waves to create images of the inside of your body; a transvaginal ultrasound involves inserting a finger-shaped device called a transducer into your vagina
• MRI scan — this uses powerful magnets and radio waves to create images of the inside of your body and can help detect endometrium tissue lining your abdomen or in your organs

Imaging tests do not always detect endometriosis. The only definitive way to diagnose endometriosis is with a procedure called a laparoscopy. This is a type of keyhole surgery, performed under general anaesthesia. Small cuts are made into your abdomen, through which a thin, flexible, telescope-like tube with a camera and a light on the end (a laparoscope) is inserted to look for endometrium tissue. Special surgical instruments can also be inserted to collect a tissue sample (biopsy) for examination in a lab. 

Rectovaginal endometriosis treatment

There is no cure for rectovaginal endometriosis, however, treatments are available to help manage your symptoms. This usually involves a combination of medication and surgery.

Hormone treatment

Hormone treatment improves symptoms in around two-thirds of women with rectovaginal endometriosis. However, it can cause side effects, such as bloating, headaches and weight gain. 

Hormone treatments work by reducing the build-up of endometrium tissue. However, they also prevent pregnancy and therefore do not improve fertility. They usually take several months to work. 

Types of hormone medications include:

• Birth control pills, patches or rings containing progesterone
• Danazol — this drug is not commonly used today due to its side effects, which includes adverse effects on blood cholesterol levels
• Gonadotropin-releasing hormone (GnRH) agonists
• Progestin injections

Painkillers

Over-the-counter pain medications can help manage pain caused by endometriosis. However, for severe types of endometriosis, which includes rectovaginal endometriosis, this isn’t an effective long-term treatment.

Surgery

If you have severe rectovaginal endometriosis, your doctor may recommend surgery to remove the endometrium lesions. This is often performed via a keyhole procedure where small cuts are made into your abdomen through which a laparoscope can be inserted, alongside special surgical instruments. 

Removing the endometrium tissue that has grown outside your womb has been shown to significantly improve pain caused by the condition. 

Different techniques are used during rectovaginal surgery, depending on the location of your lesions. Your surgeon may use: 

• Discoid excision — a disc containing the tissue affected by endometriosis is cut out and the opening closed; this is used to remove small patches of endometrium tissue eg in the bowel
• Shaving — a sharp instrument is used to remove lesions, however, some endometrium tissue may still be left behind
• Resection — part of your intestine where endometrium tissue has grown is removed and then the bowel is reconnected together

Treating complications

In rare cases, rectovaginal endometriosis can cause a blockage of the intestines. This needs treatment, which may include antibiotics, fluids given via a vein (intravenous) and/or surgery.

Rectovaginal endometriosis complications

Every surgery comes with complications. For rectovaginal surgery, complications include:

• Bleeding in the abdomen
• Chronic constipation 
• Difficulty passing stools
• Endometriosis symptoms that persist despite surgery and need further surgery
• Formation of an abnormal connection (fistula) between your vagina and rectum or other organs
• Leakage around the reconnected bowel

Rectovaginal endometriosis outlook

As there is no cure for rectovaginal endometriosis, most women will need to manage their symptoms using medication and/or surgery to reduce the effect endometriosis has on their quality of life, which can be significant.

Even after rectovaginal surgery, your symptoms may return. However, hormone treatments can slow down the growth of new endometrium tissue.

It is important to have regular appointments with your doctor to track your symptoms and adapt your treatment plan if needed.