A Patient with Hematochezia and Intestinal Obstruction

Endometriosis of the bowel is indicated by the presence of an endometrial-like gland and stromal cells in the intestinal wall. The occurrence of bowel endometriosis in the general population is unknown, though it is estimated to afflict 3.8-37% of women with endometriosis. 1 Intestinal endometriosis may affect the ileum, appendix, sigmoid colon and rectum, though it occurs most frequently in the rectosigmoid colon (50-90%). 1 Associated symptoms vary according to the site of involvement, as well as the size and depth of infiltration into the bowel wall. Symptoms usually include abdominal pain, bloating, nausea, vomiting, fecal tenesmus, painful defecation, alternating constipation and diarrhea, and rectal bleeding. 2 Transvaginal ultrasound, CT scanning, MRI, and PET scanning are required to confirm diagnosis. 3 Sigmoidoscopy and colonoscopy have limited value in the diagnosis of intestinal endometriosis, since it is rare for lesions to infiltrate the mucosa. 1 It is important, however, to exclude the presence of colorectal cancer and to assess any bowel stenosis. In the current case, we misdiagnosed intestinal endometriosis as colorectal cancer prior to surgery, based on the presence of hematochezia, and on sigmoidoscopic and radiologic findings, which were suggestive of invasive rectal malignancy. Moreover, sigmoidoscopic biopsies were inconclusive. A definitive diagnosis could only be made on the basis of pathologic analysis of surgical specimens. In women of reproductive age, therefore, clinical suspicion of bowel endometriosis is important in cases where an intestinal mass is detected with bleeding or intestinal obstruction.