Endometriosis and IBS


Dr. Jane Varney - Research Dietitian, 09 March 2021

What is endometriosis

Endometriosis is a chronic, inflammatory gynaecological condition that causes significant pain and infertility. It is surprisingly common, affecting 1 in 10 women during their reproductive years, and approximately 176 million women worldwide. 

Endometriosis occurs when tissue that normally lines the uterus (known as the endometrium), grows in and around other organs in the body. These ‘stray’ endometrial tissues are known as endometrial ‘implants’ or ‘lesions’. Organs affected by endometriosis include the ovaries, fallopian tubes, bowel, the lining of the pelvis, cervix, vagina, vulva, ureters and bladder.

As the stray endometrial tissue implants and grows, it continues to behave as it does inside the uterus - thickening, breaking down and bleeding with each menstrual cycle. But because the tissue can’t exit the body like normal menstrual blood does, it remains trapped in the pelvis where it causes irritation and inflammation in the surrounding pelvic organs. The presence of stray tissue also causes the formation of scarring and ‘sticky’ adhesions that bind pelvic organs together. As a result, normal bodily functions such as ovulating, having sex, and going to the toilet can become extremely painful, and fertility can be compromised. 


While the precise cause of endometriosis is not known, there are a range of factors that put women at increased risk of developing this condition. Known as ‘risk factors’, these include:

  • Family history of the condition
  • Early menstruation (before age 11)
  • Late menopause 
  • Short menstrual cycles (less than 27 days)
  • Long and heavy menstrual periods (more than seven days)
  • Never giving birth
  • Low body weight
  • Elevated oestrogen levels 
  • Abnormalities in the reproductive tract that prevent the normal passage of menstrual blood flow out of the body.


There are a range of common symptoms associated with endometriosis. These include:

  • Painful periods
  • Pain during or around ovulation
  • Pain during or after sex
  • Pain in the pelvic area, lower back, or legs
  • Pain with bowel movements or urination
  • Heavy or irregular menstrual bleeding 
  • Abdominal bloating and discomfort
  • Nausea
  • Fatigue
  • Altered bowel habit (diarrhoea, constipation or both)
  • Difficulty falling pregnant (infertility)

The type of endometriosis symptoms experienced varies depending on the location of the stray endometrial tissue. Symptom severity also varies from mild to severe, although symptom severity is not a good indicator of the extent of the condition, as women with mild symptoms can have severe disease and women with severe symptoms can have mild disease.

Overlap between IBS and endometriosis

By now you might be wondering why a blog dedicated to the FODMAP diet for IBS might be discussing endometriosis. There are a few reasons for this:

The two conditions share common symptoms (e.g. visceral hypersensitivity, bloating, diarrhoea or constipation, pain on defaecation, nausea, and·reduced quality of life). This makes distinguishing between the two conditions difficult, raising the possibility of misdiagnosis and/or delayed diagnosis. 

Also, because gastrointestinal symptoms are common in endometriosis, a low FODMAP diet is often used to manage these symptoms. While research is underway to determine the efficacy of a FODMAP diet in this population, we don’t yet know if it works. 

Because of these overlapping symptoms, it is recommended that endometriosis is ruled out before a diagnosis of IBS is made in women in their reproductive years. Red flags that signal the possible presence of endometriosis include:

  • Pain during or after sex
  • Heavy or irregular menstrual bleeding 
  • Pain in the pelvic area, lower back, or legs
  • Exacerbation of bowel symptoms with menstruation
  • Family history of endometriosis
  • Difficulty conceiving


If you suspect you have endometriosis, it is important to seek help. See your GP and ask for a referral to a gynecologist. While many women wait 7-10 years before receiving a diagnosis, early diagnosis and treatment can reduce the severity of the condition. The only way to accurately diagnose endometriosis is with a laparoscopy. This ‘keyhole’ surgical procedure involves the insertion of a thin tube (telescope) with a light (laparoscope) into the abdomen via a small cut in the belly button. The gynaecologist can then see if there are any endometrial deposits inside the pelvis. If endometriosis is detected, it is removed during the procedure, often providing immediate symptom relief. 


There are a range of treatments available to women with endometriosis, including:

  • Surgery to remove endometrial tissue, repair damage caused by this tissue and/or improve fertility
  • Hormone therapy such as the contraceptive pill to reduce pain and reduce the severity of endometriosis 
  • Medication such as anti-inflammatory agents to manage pain
  • Lifestyle therapies - while there is no direct evidence to suggest that lifestyle therapies are effective, many women feel better when they make changes to become or stay healthy. These can include stress management, getting enough sleep, exercise and healthy eating. 
  • Also, as mentioned, because some women with endometriosis experience IBS-like symptoms, a low FODMAP diet is often used to manage gastrointestinal symptoms associated with endometriosis. While many women report this diet helps their symptoms, more research is needed to confirm these observations. 

Take home messages

Endometriosis is a surprisingly common condition, affecting one in 10 women. Although effective treatments are available, mis-diagnosis and delayed diagnosis are common. If you suspect you have endometriosis, seek help. We recommend you see your GP and get a referral to a gynecologist. 

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