Inflammatory Bowel Disease and Endometriosis: Diagnosis and Clinical Characteristics

Background/Objectives: Endometriosis and inflammatory bowel disease (IBD) share some epidemiological, clinical and pathogenetic features. A differential diagnosis between pelvic endometriosis and IBD may be challenging, even for expert clinicians. In the present review, we aimed to summarize the currently available data regarding the relationship between endometriosis and IBD and their possible association. Methods: The PubMed and Scopus database were considered, by searching the following terms: "Crohn's Disease", "Ulcerative Colitis", "Endometriosis", "Adenomyosis", and "Inflammatory Bowel Disease", individually or combined. Full-text papers published in English with no date restriction were considered. Results: Few studies have researched the possible association between endometriosis and IBD. Both conditions are characterized by chronic recurrent symptoms, which may be shared (abdominal pain, fatigue, infertility, menstrual irregularities, diarrhea, constipation). Deep infiltrating endometriosis (DIE) can cause bowel symptoms. In a large Danish study, a 50% increased risk of IBD was observed in women with endometriosis. A missed diagnosis of endometriosis and an increased risk of endometriosis has been reported in IBD. Current evidence does not support an association between endometriosis and IBD characteristics. However, IBD may be associated with DIE, characterized by pelvic symptoms (dyschezia, dyspareunia). Preliminary observations suggest an increased IBD risk in patients with endometriosis treated with hormonal therapy. Conclusions: Current findings suggest that a careful search is needed for concomitant endometriosis in subgroups of patients with IBD showing compatible symptoms and vice versa. A multidisciplinary approach including dedicated gastroenterologists and gynecologists is required for a proper search for IBD and endometriosis in subgroups of patients. This approach may avoid diagnostic delays or overtreatments for these conditions.