Endometriosis and irritable bowel syndrome (IBS) are two conditions that can cause similar symptoms like abdominal pain and bloating. Because endometriosis is hard to diagnose, it is sometimes misdiagnosed as IBS.

Despite their similar symptoms, endometriosis and IBS are distinctly different conditions with different causes. In endometriosis, tissue similar to the uterine lining grows elsewhere in the body. This can cause severe pain as well as bleeding between periods.

Conversely, IBS is a disorder of the digestive system that can cause abdominal pain, bloating, and changes in bowel habits.

It is possible to have both conditions at the same time. In some cases, doctors diagnose people with the previously mentioned symptoms with IBS when in actuality, they have endometriosis.

Both conditions can be difficult to identify, and there are no simple blood tests or scans that can diagnose them.

Read on to learn more about the differences between endometriosis and IBS, their respective symptoms, and how to talk with a doctor.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

A venn diagram of endometriosis and IBS.Share on Pinterest
Infographic by Bailey Mariner

IBS and endometriosis are different conditions that share some common symptoms.

Endometriosis is a gynecological disorder affecting around 10–15% of people assigned female at birth.

It causes endometrial-like tissue to grow elsewhere. This tissue can attach to other organs and surfaces in the pelvis, leading to pain, inflammation, and scarring. If it grows in the bowel, it can cause IBS-like symptoms, including stomach pain, bloating, and pain or difficulty when going to the bathroom.

IBS is a common digestive disorder that causes abdominal pain, bloating, and altered bowel habits. While it affects people of all sexes, it is more prevalent among females.

Those with endometriosis are more likely to have IBS than those without. There are a variety of reasons why this is, such as:

  • IBS is more common in females, and endometriosis is a condition primarily affecting females.
  • Some people with endometriosis are misdiagnosed with IBS and do not have IBS at all.
  • IBS and endometriosis share underlying causes and risk factors that researchers do not yet understand.

Because there is limited research on both of these conditions, their underlying causes, and the links between the two, experts do not know exactly why this is.

Doctors may find it challenging to distinguish between endometriosis and IBS because they share common symptoms.

The symptoms of endometriosis include:

  • pelvic pain that gets worse around menstruation
  • pain during or after sex
  • painful bowel movements or urination
  • fatigue
  • fertility issues

The symptoms of IBS include:

  • abdominal pain or cramping that gets worse after eating
  • bloating
  • constipation
  • diarrhea
  • mucus in the stool

One way to distinguish the symptoms is that endometriosis pain is cyclical, which means it varies at different stages of the menstrual cycle. It typically gets worse before menstruation and lessens following menstruation. However, as endometriosis advances, the symptoms can become more constant.

Endometriosis is notoriously difficult to diagnose. Studies have found that there is frequently a long delay between the onset of symptoms and a diagnosis. Many people wait years and work with multiple doctors before reaching an endometriosis diagnosis.

One reason for this is that the symptoms of endometriosis resemble other conditions. Some of these include IBS, pelvic inflammatory disease, and ovarian cysts.

Diagnosing endometriosis is also a lengthy and invasive process. In order to diagnose the condition, a doctor will first aim to rule out other conditions with blood tests, pelvic exams, ultrasound scans, and other imaging tests.

The only way to definitively diagnose the condition is with keyhole surgery, also called a laparoscopy.

In a laparoscopy, the doctor inserts a small camera into the pelvis through a small incision in the belly button. This allows them to directly visualize any endometrial-like tissue growing outside of the uterus.

While this can diagnose the condition, it is a serious and invasive procedure, so some doctors are hesitant to perform it.

Because it is so difficult, slow, and expensive to diagnose endometriosis, some doctors may mistakenly diagnose the condition as IBS if a person has symptoms such as abdominal pain and bloating.

There is no evidence that IBS can cause endometriosis.

However, there is a bi-directional relationship between the conditions. It seems that IBS is more common in individuals with endometriosis, and gynecological issues are more common in those with IBS.

Some studies show that in menstruating people with IBS, approximately 45% experience menstrual cramps, and 35% experience premenstrual syndrome (PMS). Around 30% of people with IBS report a history of chronic pelvic pain.

Despite this, there is currently no research showing that IBS causes endometriosis or vice versa. However, because there is limited research on this topic, experts may learn more about the link in the future.

If a person has an IBS diagnosis but has endometriosis symptoms, they should contact a doctor.

Some people find that talking with a healthcare professional about endometriosis can be difficult and overwhelming, so it can be useful to prepare for an appointment by tracking one’s symptoms alongside menstrual cycles and writing down questions in advance.

Sample questions to ask a doctor include:

  • What are the possible causes of my symptoms?
  • What tests do I need to confirm the diagnosis? What do the possible results mean for me?
  • What is the best way to treat my condition?
  • Are there any foods I should avoid if I have IBS?
  • Are there any activities that I should avoid if I have endometriosis?
  • What are the potential side effects of the medications you are prescribing me?
  • When can I expect my symptoms to improve?
  • Are there any long-term complications associated with my condition?

Endometriosis and IBS are two different conditions that share common symptoms, such as pain, cramping, bloating, and constipation or diarrhea. People with endometriosis are more likely to also have IBS, and those with IBS are more likely to have menstrual problems.

There is no singular test for either condition, and both can be relatively difficult to diagnose. If a person thinks that they may have endometriosis or IBS, they should contact a doctor.