Endometriosis is a chronic inflammatory condition associated with chronic pelvic pain (CPP), dysmenorrhea and bowel-related symptoms. Significant overlap exists between endometriosis and other benign abdominal pathologies, including irritable bowel syndrome (IBS). We aimed to identify the prevalence of IBS-related symptoms in a group of women undergoing either diagnostic or therapeutic surgical interventions for CPP.

This ethically approved (IRAS 294803) prospective case-control study was undertaken between 8th November 2021 and 22nd February 2023. Premenopausal women presenting to the Liverpool Women's Hospital for surgical investigation and management of CPP completed an electronic questionnaire containing questions pertinent to the Rome IV diagnostic criteria for IBS and the validated British Society for Gynaecological Endoscopy (BSGE) endometriosis and pelvic pain questionnaire. Patients were grouped according to surgical findings: control (no endometriosis) (n = 49), superficial endometriosis (SE) ( n = 21), or deep endometriosis (DE) ( n = 19).

Sixty-six (74.2%) women included in this study had a concurrent diagnosis of IBS. The prevalence of IBS was significantly higher in patients without surgical evidence of endometriosis (83.7% vs. 62.5%, p = 0.02). When considering endometriosis subtypes, patients with DE were less likely to meet the diagnostic criteria for IBS than those with SE and no endometriosis (57.9% vs. 66.7% vs. 83.7%, p = 0.062).

Patients presenting with CPP, regardless of the underlying diagnosis of endometriosis, have a high prevalence of concomitant IBS. Clinicians should discuss bowel symptoms with all CPP patients and consider commencing concurrent IBS treatments as appropriate to improve patient symptoms.