255. When Everything Hurts: Co-Occurrence of Irritable Bowel Syndrome And Endometriosis In Adolescents

Abstract

While the exact cause of endometriosis remains unknown, patients with endometriosis often exhibit central hypersensitization and alteration in immune surveillance. Patients with irritable bowel syndrome (IBS) have a similar biobehavioral milieu with alterations in visceral hypersensitivity, central sensitization of pain, and altered immune function contributing to symptoms. Given these similarities, young women are commonly referred for both gastroenterologic and gynecologic evaluations. We hypothesized that girls with endometriosis would have a high risk of comorbid IBS. Our aim was to describe the prevalence and predictors of IBS among adolescents with laparoscopically-diagnosed endometriosis. The Women’s Health Study: from Adolescence to Adulthood (A2A) is a longitudinal cohort study enrolling premenopausal females with and without endometriosis. Our analytic population included females aged 11-21 y, enrolled April 2015 - February 2017. Participants who were surgically diagnosed with endometriosis comprised the case group; participants without endometriosis comprised the control group. As part of study enrollment, participants completed an extensive online health questionnaire regarding a wide variety of medical history, lifestyle, and environmental exposures as well as symptom experience and treatments. Our primary exposure was the diagnosis of IBS, made by either 1) participant self-reported physician diagnosis of IBS, or 2) meeting the 2016 Rome IV diagnostic criteria for IBS. Pelvic pain was measured using a numeric rating scale (NRS, 0-10 score). We calculated crude and adjusted odds ratios (aOR) and 95% confidence intervals (CI) using unconditional logistic regression. Overall, 19% of the cohort (198 adolescents with endometriosis,75 healthy controls) met our diagnostic criteria for IBS. Of the adolescents with endometriosis, 46 (23%) young women had comorbid IBS compared to 7 (9%) healthy controls. The odds of endometriosis were three times higher among patients with a diagnosis of IBS compared to those without [aOR=3.32; CI=1.08, 10.19]. Patients who met Rome IV criteria but did not carry a clinician’s diagnosis of IBS had a 7-fold higher odds of endometriosis (aOR=7.23, CI=1.45, 35.97). Among participants with both IBS and endometriosis, the average general pelvic/lower abdominal pain NRS score was 8.0 (SD=3.1). For women with IBS but not endometriosis, the average NRS score was 4.7 (SD=4.4). Among women with IBS, for each 1-point increase in the general pelvic/lower abdominal pain NRS score, the odds of endometriosis increased by 28% [aOR=1.28, CI=1.03, 1.59). Neither depression, anxiety, nor both altered the odds of endometriosis in females with IBS. We observed statistically significant greater odds of laparoscopically-confirmed endometriosis among those with IBS. Among adolescents with IBS, a linear relationship between the severity of general lower abdominal pain and the odds of surgically-confirmed endometriosis was demonstrated. Mood disorders did not impact the likelihood of IBS. Evidence is emerging to support a unified concept of these functional pain disorders. Increased awareness and screening for both IBS and endometriosis by pediatricians, pediatric gastroenterologists, and gynecologists will likely speed diagnosis and improve outcomes in patients and advance understanding of both of these complex disorders.