Endometriosis as an Uncommon Cause of Intestinal Obstruction-A Comprehensive Literature Review

The prevalence of intestinal endometriosis has been estimated to be between 3% and 37% of all endometriosis cases. Cases of intestinal occlusion due to endometriosis foci on the small bowel and on the large bowel are even rarer, with a reported prevalence of 0.1-0.7%. The aim of this literature review was to summarize the available published evidence on the diagnosis, characteristics, and management of intestinal occlusion due to endometriosis. The search on PubMed retrieved 295 records, of which 158 were rejected following a review of the title and abstract. After reviewing the full text, 97 studies met the Population, Intervention, Comparator, Outcomes, and Study (PICOS) criteria and were included in the analysis. The total number of patients with bowel occlusion due to endometriosis included in the studies was 107. The occlusive endometrial foci were localized on the ileum in 38.3% of the cases, on the rectosigmoid in 34.5% of the cases, at the ileocecal junction and the appendix in 14.9% of the cases, and at the rectum in 10.2% of the cases. Only one case reported large bowel obstruction by endometriosis of the hepatic flexure of the colon extending to the transverse colon (0.9%), and in one case the obstruction was caused by an omental giant endometrioid cyst compressing the intestines. We identified six cases of postmenopausal females with acute bowel obstruction due to endometriosis. Malignant degeneration of endometriosis was also identified as a cause of intestinal occlusion. The mechanisms of obstruction include the presence of a mass in the lumen of the intestine or in the wall of the intestine, extrinsic compression, adhesions, or intussusception.