Intestinal endometriosis as an unusual cause of small bowel obstruction and abdominal pain

Purpose: Purpose: Gastrointestinal involvement by endometriosis is uncommon, but should be considered on the differential for acute abdominal pain in women. A 45-year-old Caucasian female with erosive gastritis, gastroesophageal reflux, uterine fibroids, interstitial cystitis, and a recent history of terminal ileitis presented to the emergency room with acute onset of severe progressive abdominal pain, nausea and vomiting that began after a large, spicy meal. She reported a similar episode eight months prior. At that time, computer tomography (CT) of the abdomen revealed thickening of the proximal and terminal ileum with moderate amount of free pelvic fluid. The pain resolved spontaneously within several hours. Subsequent EGD and colonoscopy were normal. On examination the abdomen was soft without palpable masses, but tender to palpation in the hypogastrium and left lower quadrant. Bowel sounds were normal. A CT showed skip lesions with mural thickening in the middle and distal ileum and an associated small bowel obstruction, suspicious for Crohn disease. Serology including IgA, IgG ASCA antibodies (Abs), neutrophilic specific Abs, myeloperxidase and proteinase-3 Abs were negative. The C-reactive protein and erythrocyte sedimentation rate were also normal. Stool and urine cultures were collected and negative. Furthermore Vitamin D level was normal. Follow up colonoscopy with push ileoscopy showed multiple submucosal cystic lesions with normal overlying mucosa. Exploratory laparoscopy was recommended. The procedure revealed lesions involving the muscularis propria at the terminal ileum and 40 cm proximally which were confirmed by intraoperative pathology to be intraintestinal endometriosis. Subsequently a partial small bowel resection was performed. Discussion: Intestinal endometriosis can present as acute abdominal pain and small bowel obstruction or masquerade as Crohn disease on CT findings.