S535 Evaluating Irritable Bowel Syndrome Symptoms and Pelvic Floor Dysfunction in Patients With Deep Endometriosis of the Posterior Pelvis

Introduction: The overlap of endometriosis and irritable bowel syndrome (IBS) diagnoses is well documented. Women with endometriosis have a 2.4-fold risk of fulfilling IBS criteria and there is a 3-fold risk of endometriosis diagnosis in women with IBS. Deep endometriosis (DE) can infiltrate organs in the posterior compartment including the rectosigmoid colon, potentially leading to bowel symptoms. We aim to evaluate prevalence of IBS and pelvic floor dysfunction (PFD) in patients with DE. Methods: Identified women with endometriosis protocol MRI from 9/2015-7/2018. GI symptoms collected via validated survey at initial visit. MRI reports reviewed to identify posterior DE. IBS defined as reported change in bowel frequency and improvement/worsening of pain with defecation. PFD by MRI evaluated using rectal gas volume (RGV) with cutoff >900 m2 (PPV 77%). Results: 148 patients had baseline survey and endometriosis on MRI. Of these, 56(37.8%) patients met criteria for “baseline IBS”. Prior IBS diagnosis was reported by 21(14%) patients, but only 11(52%) had “baseline IBS”. A majority(80%, n=45) of “baseline IBS” patients did not have prior IBS diagnosis. These patients were not more likely to have experienced obstetric complications(21% vs.19%, OR 1.12, 95%CI 0.45-2.73, p=0.95). “Baseline IBS” was not associated with a higher likelihood of finding posterior DE (Figure). However, improvement of pain with defecation was significantly associated with posterior DE with OR 2.4 (95%CI 1.23-4.71, p= 0.011). Of the 153 patients with MRIs, 93 had endometriosis, 44 had DE. 13(30%) patients with DE had RGV >900 m 2, 1 underwent anorectal manometry(ARM). 10(20%,n=49) endometriosis patients without DE had RGV >900 m2. 20(33%,n=60) patients without endometriosis had RGV >900 m2, 16 underwent ARM. Of those with “baseline IBS”+DE, 37%(n=7/19) had RGV >900 m2. Evaluation of 17 ARMs showed nonsignificant differences in patients with and without DE (Table) due to limited sample size. Conclusion: Historic diagnosis of IBS does not predict GI symptoms at time of endometriosis diagnosis. Pain improvement with defecation was significantly associated with a higher likelihood of posterior DE. Similar percent of patients with DE and without endometriosis had PFD with RGV >900 m2, with limited further evaluation suggesting underdiagnosis. On ARM, there is a small signal towards higher resting pressures and failed balloon expulsion test in women with DE, but statistically insignificant due to low power—further studies are needed.Figure 1.: Irritable Bowel Syndrome symptoms and Deep Endometriosis Table 1. - Anorectal manometry with balloon expulsion test in patients with and without deep endometriosis Balloon Expulsion Test Deep Endometriosis (n=4) Deep Endometriosis (n=4) P – value Failed Balloon Expulsion test 1 (25%) 4 (31%) 0.067 Anorectal Manometry Measure Deep Endometriosis (n=4) No Deep Endometriosis (n=13) P – value Mean sphincter pressure (Rest), mmHg (median, IQR) 99.25 (94.25; 108.5) 92.90 (84.3; 100.6) 0.3082 Max sphincter pressure (Squeeze), mmHg, (median, IQR) 195.3 (177.65; 228.35)50.7 IQR 177.9 (146.3; 255.5)109.2 IQR 0.5713 Rectoanal pressure differential, mmHg (median, IQR) -55.75 (-81.45; -35.8)-45.65 IQR -64.8 (-84.5; -48.7)-35.8 IQR 0.5713 First sensation, (median, IQR) 20 (20; 30)10 IQR 20 (20; 40)20 IQR 0.7767 Urge to defecate, (median, IQR) 40 (30; 65)35 IQR 40 (40; 60)20 IQR 0.6558 Discomfort (median, IQR) 75 (60; 120)60 IQR 60 (60; 90)30 IQR 0.4967