Endometriosis of the sigmoid colon and rectum

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.

Mucosal changes in the large bowel with endometriosis: a possible cause of misdiagnosis of colitis?

Endometriotic deposits are not uncommon in the large bowel of women. Because the symptoms produced by endometriosis may lead to investigation by colorectal endoscopic biopsy, the aims of this study were to assess the range of mucosal abnormalities that may occur and to determine whether this could represent a significant potential diagnostic problem. We found mucosal changes in eight of 10 cases of colorectal endometriosis; however, the abnormalities (ulceration, gland architectural disturbance, crypt abscess formation, increased inflammatory cell presence, and smooth muscle fibers between glands in the mucosa) were focal and directly related to endometrial deposits. In one case an abnormal colonic biopsy specimen from a patient with endometriosis supported the erroneous clinical diagnosis of Crohn's disease. Comparing a group of women with endometriosis to a group with adenomyosis of the uterus showed that although more women with endometriosis have endoscopic large bowel biopsies, there was no significant excess of biopsy specimens showing inflammatory changes. Our conclusion is that the endometriosis of the large bowel can masquerade as inflammatory bowel disease or ischemic changes and the possibility should be borne in mind, particularly in cases with atypical clinical features or very focal histological changes.

Cyclical rectal bleeding in colorectal endometriosis

Three case reports of cyclical rectal bleeding in endometriosis affecting rectum and sigmoid colon emphasize the close relationship between such cyclical bleeding and intestinal endometriosis. The cause of bleeding, however, is still unclear. The predilection of endometriotic deposits for the outer layers of the bowel wall suggests that mucosal involvement is not a prerequisite for rectal bleeding. The frequent absence of identifiable intramural haemorrhage casts doubt on the premise that intestinal endometriotic deposits 'menstruate'. The cause may simply be a transient tear in normal mucosa due to swelling of an underlying endometriotic deposit at the time of menstruation.