Advances in bowel endometriosis: epidemiology, pathogenesis, diagnosis, treatment, and future perspectives

Bowel endometriosis (BE), the most common extra-pelvic manifestation of endometriosis and one of the most challenging subtypes of deep infiltrating endometriosis (DIE), is defined by endometrial glands and stroma infiltrating the bowel wall with involvement of the muscularis propria. Rectosigmoid involvement accounts for approximately 90% of all intestinal lesions. BE causes progressive pelvic pain, severe gastrointestinal dysfunction, and subfertility, substantially impairing the physical and psychological well-being of women of reproductive age. This narrative review comprehensively summarizes recent advances in the epidemiology, multifactorial pathogenesis (retrograde menstruation, coelomic metaplasia, immune dysregulation, neuroinvasion, gut microbiota, and somatic driver mutations), clinical presentation and quality-of-life impact, multimodal imaging strategies (International Deep Endometriosis Analysis [IDEA], enhanced ultrasonography, magnetic resonance imaging [MRI], endoscopic ultrasonography), individualized treatment (hormonal therapy, shaving, discoid resection, segmental resection), and multidisciplinary team (MDT) management of BE. We additionally discuss classification/staging systems (the ENZIAN score), surgical decision-making algorithms including ultrasound-guided classification (UBESS) and degree of muscular infiltration, complementary and nutritional therapies, fertility preservation, long-term prognosis and recurrence (including persistent symptoms despite surgery), and future precision-medicine directions, accompanied by a graded appraisal of the quality of available evidence. A particular focus is placed on delayed diagnosis, which remains a major contributor to disease burden.