EP524 - Preoperative Evaluation of Endometriosis: Retrospective Review of Colonoscopy and Intraoperative Findings

Purpose/Background: Bowel endometriosis is challenging to diagnose preoperatively due to its variable presentation and the limited sensitivity of standard imaging and endoscopic modalities. Colonoscopy, MRI, and CT are frequently used in preoperative evaluation, but their ability to predict disease severity and postoperative outcomes remains uncertain. The relationship between preoperative bowel symptoms, endoscopic findings, and intraoperative disease extent is also poorly defined. This study evaluates the correlation between preoperative symptoms, colonoscopic findings (inflammation, stricture, and polyps), and surgical outcomes in patients undergoing colorectal surgery for endometriosis.

Methods/Interventions: A retrospective review was performed of 68 patients who underwent colorectal surgery for endometriosis between May 2021 and September 2025 at a single institution. Data included demographics, presenting symptoms, imaging (MRI, CT, ultrasound), colonoscopy findings (inflammation, stricture, polyps), intraoperative findings, pathology, and 30-day postoperative outcomes. Patients were stratified by the presence or absence of preoperative bowel symptoms and colonoscopic abnormalities. Comparisons between groups were performed using Fisher's exact test, with statistical significance defined as p < 0.05.

Results/Outcomes: Forty-nine patients (72%) reported preoperative bowel symptoms such as pain with defecation, constipation, or rectal bleeding, while 16 (24%) did not. Rates of bowel resection were similar between symptomatic and asymptomatic patients (35% vs 50%, p = 0.3), as were excision without resection (27% vs 19%, p = 0.7), ostomy formation (6.3% vs 0%, p = 0.6), postoperative ileus (2.1% vs 0%, p > 0.9), readmission (11% vs 6.3%, p > 0.9), and 30-day infection (4.1% vs 0%, p > 0.9). Colonoscopic inflammation was present in 22 patients (32%) and associated with higher resection rates (59% vs 26%, p = 0.012) and fewer excisions without resection (9.1% vs 32%, p = 0.047). Stricture was identified in six patients (9%), correlating with markedly higher resection (83% vs 33%) and ostomy rates (50% vs 0%), and increased postoperative ileus (20% vs 0%) and readmission (25% vs 11%) despite small numbers. Polyps were identified in 13 patients (19%), all benign, emphasizing the importance of colonoscopy for concurrent colorectal screening prior to surgery. All patients, regardless of symptoms or colonoscopic findings, had intraoperatively and pathologically confirmed endometriosis.

Conclusion/Discussion: Preoperative bowel symptoms alone were not reliable predictors of disease severity or surgical extent in patients with bowel endometriosis. In contrast, colonoscopic findings-particularly inflammation and stricture-correlated with more advanced disease, higher resection rates, and greater postoperative morbidity. The incidental detection of benign polyps in nearly one-fifth of patients underscores the added value of colonoscopy as a screening tool before colorectal surgery. Despite its limited diagnostic sensitivity for endometriotic lesions, colonoscopy remains valuable for identifying coexisting pathology and aiding surgical planning. A multidisciplinary preoperative approach integrating symptoms, imaging, and endoscopic evaluation remains essential for optimal management of bowel endometriosis.