What Is the Connection Between Endometriosis and IBS?

Endometriosis is a condition that can have many symptoms. In many cases, endometriosis occurs along with other conditions. For example, a number of people living with endometriosis are also affected by irritable bowel syndrome (IBS).

According to our 3rd Endometriosis In America survey, 30 percent of endo warriors have also been diagnosed with IBS. Many survey respondents have also experienced IBS symptoms:

• 70 percent have diarrhea.
• 75 percent have constipation.
• 76 percent have nausea.
• 10 percent have chronic fatigue syndrome.
• 12 percent have fibromyalgia.

Similarly, according to our 3rd IBS In America survey, 12 percent of respondents have also been diagnosed with endometriosis. Understanding the connection between endometriosis and IBS can help you get the right care and treatment.

What is IBS?

The term IBS includes a group of different symptoms that are related to bowel movements. Bowel issues with IBS often improve after a person has passed stool.¹

IBS is a functional disorder. This means there is no specific physical blockage or problem with a person’s intestines. Instead, they are just not working as expected. If a person with IBS was to get a colonoscopy (a test that looks at the inside of the colon), they may have no obvious changes or problems inside their intestines.¹

This is different from inflammatory bowel disease (IBD). This includes Crohn’s disease and ulcerative colitis. In IBD, a person often has bloody diarrhea and ulcers throughout their intestines and colon.¹

Shared symptoms of IBS and endometriosis

IBS and endometriosis share many symptoms. This is especially true for those with endometriosis lesions or tissue that has implanted on the bowel walls. Several of these shared symptoms include:^2-5

• Painful bowel movements
• Abdominal cramping
• Constipation
• Diarrhea
• Excess gas or bloating
• Nausea
• Abdominal pain
• Rectal pain

Tracking when symptoms occur can help identify the difference between IBS and endometriosis. For example, a person with endometriosis with bowel issues may have worse symptoms around her period or at different points during the menstrual cycle. On the other hand, a person with IBS may have symptoms all the time or randomly. However, it is not always easy to tell the difference between IBS and endometriosis by symptoms alone. This is because many symptoms overlap. It is common for both conditions to be misdiagnosed.^2-5

Why might endometriosis and IBS be related?

As mentioned, both conditions share many of the same symptoms. This makes it easy to confuse 1 condition with the other. While it is possible to have both IBS and endometriosis at the same time, it is also possible to only have 1 condition but be diagnosed with both. If only 1 of the conditions is truly present, it may be possible to be diagnosed with the other condition first, before the real underlying cause is found.^2-5

These 2 conditions can be very hard to separate, since there are no screening tests used to diagnose them. Diagnosis is often based on symptoms alone, unless endometriosis is diagnosed during surgery.^2-5

In many cases, endometriosis tissue implanting directly on the bowel wall may cause both conditions to occur at the same time. It is common for endometriosis tissues to implant in areas that impact the bowels. This includes the:^2-5

• Inside of the abdominal wall
• Space in the abdomen between the rectum and the uterus (called the posterior cul-de-sac or pouch of Douglas)
• Appendix
• Rectum
• Colon

As the endometriosis tissue in these areas breaks down, it can cause problems with bowel movements and abdominal pain. This leads to symptoms that are similar to IBS symptoms.^2-5

It is still possible for a person with endometriosis to develop IBS or IBS-like symptoms even if affected tissues do not directly impact their bowels. Some doctors think that inflammation and a hormone called prostaglandin are factors. When inflammation and prostaglandin are released from endometriosis lesions, even those not on the bowels, they may cause damage and lead to bowel dysfunction and IBS.^2-5

Doctors have also suggested that long-term inflammation may make a person more likely to develop both endometriosis and IBS. Other theories on the link between the conditions have focused on nervous system issues in the gut.^2-5

What does the research say?

While more research is needed to understand the link between endometriosis and IBS, there are some common trends. About 20 percent of people with endometriosis may have direct bowel involvement, causing bowel issues. However, many people without endometriosis on the bowels may still have IBS symptoms.²

One study found that about 8 percent of endo warriors had endometriosis directly on their bowels, but 90 percent had gastrointestinal symptoms. This means that direct bowel involvement may play a role in IBS-like symptoms with endometriosis.³

Other research has found that people with endometriosis may be 2 to 3 times more likely to be diagnosed with IBS compared with those without endometriosis. The increased risk was similar for both people with endometriosis directly on the bowels and those without.⁵