Can endometriosis cause inflammatory bowel disease (IBD)?

From the Guidelines

Endometriosis does not directly cause inflammatory bowel disease (IBD), but there is a relationship between these conditions, with women with endometriosis possibly having a slightly higher risk of developing IBD due to shared inflammatory pathways and immune system dysfunction, as suggested by recent studies 1. The exact relationship between endometriosis and IBD is still not fully understood, but research suggests that endometriosis can directly affect the bowel when endometrial tissue implants on intestinal surfaces, causing symptoms that mimic IBD such as abdominal pain, bloating, constipation, or diarrhea, known as bowel endometriosis 1. Some key points to consider include:

• Endometriosis is a condition where tissue similar to the uterine lining grows outside the uterus, while IBD includes conditions like Crohn's disease and ulcerative colitis, as described in the WSES-AAST guidelines for management of inflammatory bowel disease 1.
• Bowel endometriosis can cause local inflammation, but it is distinct from true IBD, and the treatments differ significantly, highlighting the importance of consulting with both a gynecologist and gastroenterologist for proper diagnosis and treatment 1.
• The diagnosis of endometriosis is challenging due to variable presenting symptoms and nonspecific physical examination findings, and imaging studies such as expanded protocol transvaginal ultrasound (TVUS) and MRI can be useful in diagnosing and planning treatment for endometriosis, including bowel endometriosis 1. It is essential to note that while there is a relationship between endometriosis and IBD, they are distinct conditions with different treatments, and a proper diagnosis is crucial to ensure the best possible outcome for patients with persistent bowel symptoms and endometriosis, as supported by the most recent and highest quality studies 1.

From the Research

Endometriosis and Inflammatory Bowel Disease

• The relationship between endometriosis and inflammatory bowel disease (IBD) has been investigated in several studies 2, 3.
• A study published in 2015 found that endometriosis of the intestinal tract can mimic IBD both clinically and pathologically, making diagnosis challenging 2.
• Another study published in 2020 reported a positive association between endometriosis and IBD, with a 50% increase in the risk of IBD in women with endometriosis compared to the general population 3.

Shared Symptoms and Diagnostic Challenges

• Endometriosis and IBD share similar symptoms, such as abdominal pain and inflammation, which can lead to misdiagnosis or delayed diagnosis 2, 3.
• A systematic review of 23 articles found that the diagnosis of IBD in patients with endometriosis should be reevaluated over time, as the symptoms and histology of the two conditions can be similar 3.

Epidemiological Evidence

• Epidemiological studies have reported a higher prevalence of IBD in women with endometriosis, ranging from 2 to 3.4% compared to 0-1% in the control group 3.
• A large nationwide Danish cohort study found a standardized incidence ratio of 1.5 and 1.6 for Crohn's disease and ulcerative colitis, respectively, in women with endometriosis 3.

Related Conditions

• Endometriosis has also been linked to other conditions, such as irritable bowel syndrome (IBS), with a meta-analysis finding a twofold greater risk of IBS in women with endometriosis compared to those without the condition 4.
• The relationship between endometriosis and IBS highlights the importance of considering multiple conditions when diagnosing and treating women with chronic abdominal pain and inflammation 4.