Beyond borders: a case report of small bowel obstruction secondary to undiagnosed florid endometriosis

Introduction and importance: Endometriosis is a gynecological condition referring to the presence of endometrial tissue outside the endometrium with the potential of progressing to malignancy. It mostly affects pelvic organs; however, it has been described beyond the pelvis. In 10% of cases it occurs in the bowel, mostly rectum and sigmoid. Involvement of the small bowel is rare. Here we report endometriosis of the terminal ileum and appendix in a patient with no previous diagnosis of endometriosis. Case presentation: We describe a case of a 39-year-old-female who presented with abdominal pain, nausea and vomiting to the emergency department. This was on background history of intermittent abdominal pain every 2 weeks for the previous 5 months. Further investigation with computed tomography (CT) of the abdomen and pelvis showed small bowel dilatation with a polypoidal lesion obstructing the terminal ileum. On colonoscopy, no intraluminal lesions were identified in the terminal ileum. The patient underwent right hemicoloectomy. Histopathological results revealed endometriosis. The patient had uneventful recovery post-operatively and at her follow-up review at 4 weeks and 2 months from surgery. Discussion: The presentation of endometriosis of the bowel is highly variable and difficult to diagnose pre-operatively. Due to lack of specific diagnostic measures, surgical resection and histology can be the only reliable way for first-time endometriosis diagnosis presenting as small bowel obstruction. Conclusion: Extra-pelvic endometriosis should be considered as the cause of small bowel obstruction in the absence of other causes of bowel obstruction in young female patients.