Sigmoid endometriosis in a post-menopausal woman leading to acute large bowel obstruction: A case report

INTRODUCTION: Endometriosis is usually a disease involving women of reproductive age. Colonic endometriosis is a rare sequelae. It usually presents vaguely with nonspecific abdominal pain, dyspareunia, fecal tenesmus, rectal bleeding or painful defecation. There are very few case reports of sigmoid endometriosis in the literature, more so ones involving post-menopausal women. Our report highlights such a case, mimicking a malignant rectosigmoid stricture leading to a large bowel obstruction. CASE PRESENTATION: A 63 year old lady was referred by her General Practitioner for further investigation of recent altered bowel habit. She underwent an incomplete colonoscopy due to stricturing in the sigmoid. She subsequently was admitted with abdominal pain, distension and vomiting, with imaging consistent with a large bowel obstruction secondary to a stricturing mass within the rectosigmoid which was suspicious for malignancy. An emergency laparotomy and Hartmann’s procedure was performed. She had an uncomplicated post-surgical recovery. Histology revealed no underlying malignancy, but confirmed colonic endometriosis. CONCLUSION: This case report shows that colonic endometriosis, although rare, can be significantly infiltrative and lead to complications such as a large bowel obstruction. Diagnosing this condition can be challenging and usually requires histological confirmation.