Lugo, AdrianMartyn, ColinCho, Isaac S.Fraser, ScottGislason, Gardar2021-07-022021-07-022021-06-10https://hdl.handle.net/1805/26210Submitted to the American College of Gastroenterology's 2021 Annual Scientific MeetingClinical manifestations of gastrointestinal (GI) dysfunction are diverse. However, many of these symptoms such as abdominal pain and hematochezia are nonspecific and can be caused by a variety of ailments. As such, it is imperative to develop a broad differential diagnosis including conditions outside of the GI system. In this case report, we demonstrate how endometriosis was inadvertently discovered as the culprit in a patient with abdominal pain and hematochezia. A 30-year-old female with a history of endometriosis, total laparoscopic hysterectomy with left salpingo-oophorectomy, and right salpingectomy presented to the clinic with abdominal pain. It was gradual in onset, occurred 3 to 4 days monthly, and was associated with diarrhea, tenesmus, and mild hematochezia with clots. Alleviating factors included defecation and warmth. No weight loss was noted. Physical exam was significant for right lower quardrant and subprapubic tenderness. A colonoscopy was performed which demonstrated an infiltrative, submucosal, non-bleeding 3 cm mass in the proximal rectum. The terminal ileum and colon were unremarkable. An endoscopic ultrasound with biopsy via fine need aspiration of the mass was then performed. The biopsy demonstrated glands within smooth muscle bundles positive for cytokeratin 7, Ber-EP4, weak to moderate staining of the estrogen receptor, and very weak focal positivity for PAX-8, all of which was most consistent with endometriosis. The patient was subsequently referred to a surgeon for removal of the affected rectum, but she ultimately declined surgery. Her symptoms were mildly controlled with oral contraceptives, but the hematochezia persisted during her menstrual cycles. Patients often present with vague GI symptoms that are manifestations of non-GI processes. This case report demonstrates how an extra-intestinal condition was able to infiltrate through the intestinal wall to cause abdominal pain and hematochezia. We believe the patient’s symptoms stemmed from her endometriosis as she has an intact right ovary and the hematochezia was cyclical in nature. Other investigations have reported multiple segments of the bowel being affected by endometriosis, but the literature is scarce in the standardization of treatment for these cases. This report highlights the importance of potentially resecting bowel segments that are affected by endometriosis as these lesions may cause significant morbidity if the underlying condition is not treated accordingly.enAttribution-ShareAlike 4.0 Internationalhematocheziacyclicalcyclical abdominal painendometriosisPresentation