Diagnosis of Intestinal Endometriosis: A Multicenter Retrospective Study

Background: Intestinal endometriosis occurs when endometrial-like tissue infiltrates the intestinal wall, most often affecting the sigmoid colon and rectum. Methods: Between January 2012 and February 2025, patients with intestinal endometriosis who underwent surgery were examined in five tertiary referral centers: Istanbul Sultan Abdülhamid Han Research and Training Hospital, Izmir Katip Çelebi University, Bakırköy Dr. Sadi Konuk Training and Research Hospital, Başakşehir Çam and Sakura City Hospital, and Izmir City Hospital. Preoperative symptoms, demographic characteristics, menstrual status, operative times, intraoperative blood loss, surgical and pathological findings, antibiotic use, and postoperative complications were retrospectively reviewed. Results: Emergency surgery was required in a significant number of patients (n = 35, 71.4%), primarily due to intestinal obstruction or acute abdomen presentations. Resection procedures included anterior or low anterior resections for rectosigmoid involvement and colectomies for colonic disease (n = 21, 42.9%), appendectomies performed for acute appendicitis (n = 26, 53.1%), and small bowel resections for small intestinal diseases (n = 2, 4.1%). Postoperative complications were observed in 8 patients, including ileus (n = 2), infections requiring antibiotics (n = 2, Grade II), intra-abdominal abscess requiring percutaneous drainage (n = 1, Grade IIIa), bleeding requiring reoperation (n = 1, Grade IIIb), incisional hernia (n = 1, Grade IIIa), and fat necrosis (n = 1, Grade I). Histopathological examination revealed transmural (full-thickness) bowel wall involvement in three patients and muscularis propria-limited involvement in two patients. One case involved a 67-year-old postmenopausal woman who presented with bowel obstruction and required emergency surgery. Intraoperatively, a rectosigmoid stricture without a visible tumor was identified. Conclusion: Surgeons and clinicians should maintain a high index of suspicion for endometriosis in postmenopausal patients presenting with nonspecific gastrointestinal symptoms or when unexpected findings are encountered during abdominal surgery. Considering intestinal endometriosis in the differential diagnosis, even in the absence of typical risk factors such as hormone replacement therapy or a prior history of endometriosis, is essential for improving diagnostic accuracy and patient outcomes.