Endometriosis Associated with Increased Risk of Inflammatory Bowel Disease

Women with endometriosis are much more likely to develop a type of inflammatory bowel disease (IBD) than women without the reproductive disorder, researchers in Denmark have found.

The researchers began the study intending to focus solely on the connection between Crohn's disease and ulcerative colitis in women with endometriosis. Endometriosis, which afflicts up to one in 10 women, can make childbearing difficult if not impossible.

The researchers gathered data on a cohort of 37,661 Danish women who were hospitalized with endometriosis between 1977 and 2007. They followed the long-term health of the women over an average of 13 years and found that women with endometriosis have a 50% greater risk of developing an IBD than members of the general population. In the cohort, 320 of the women developed an IBD (228 ulcerative colitis and 92 Crohn’s disease). The average time between diagnosis of the reproductive disorder and development of IBD was roughly 10 years.

When the researchers looked only at women whose endometriosis was confirmed surgically, they found an 80% increase in risk of developing an IBD for up to 20 years following the diagnosis of endometriosis.

Both endometriosis and IBD are chronic inflammatory disorders with a typical onset in young adulthood. The authors noted that the association between the two disorders may be the result of common causes.

“The risk of IBD in women with endometriosis was increased even in the long term, hence suggesting a genuine association between the diseases,” write the authors, “which may either reflect common immunological features or an impact of endometriosis treatment with oral contraceptives on risk of IBD.”

This study was published online earlier this month in Gut.