How does intestinal endometriosis cause small bowel obstruction?

From the Guidelines

Intestinal endometriosis causes small bowel obstruction through the infiltration of endometrial tissue into the muscular bowel wall, leading to gastrointestinal symptoms and potential obstruction. The mechanisms by which intestinal endometriosis causes small bowel obstruction include:

• Inflammation, fibrosis, and scarring in response to hormonal fluctuations during menstrual cycles, causing progressive narrowing of the intestinal lumen
• Adhesions between loops of bowel or between the bowel and other pelvic structures, creating kinks or angulations that further compromise intestinal passage
• Invasion of the muscular layer of the bowel wall, affecting normal peristalsis and causing dysmotility
• Cyclical bleeding from endometrial implants, creating localized edema that temporarily narrows the intestinal lumen 1. The small bowel is less commonly affected by endometriosis compared to the rectosigmoid colon, sigmoid colon, cecum, and ileocecal valve, but when involved, it can lead to significant morbidity and mortality if not promptly diagnosed and treated 1.

Key Points

• Intestinal endometriosis can cause small bowel obstruction through various mechanisms
• The condition can lead to significant morbidity and mortality if not promptly diagnosed and treated
• Treatment typically involves hormonal therapy and surgical intervention to remove obstructing lesions and restore bowel patency
• The approach to treatment depends on the severity and location of the obstruction, as well as the patient's overall health status 1.

Management

• Hormonal therapy to suppress endometrial growth and surgical intervention to remove obstructing lesions and restore bowel patency are the mainstays of treatment
• The choice of treatment approach depends on the severity and location of the obstruction, as well as the patient's overall health status
• Imaging studies, such as those described in the ACR Appropriateness Criteria, can aid in the diagnosis and management of small bowel obstruction 1.

Diagnosis

• Imaging studies, such as CT or MRI, can help diagnose small bowel obstruction and identify the underlying cause
• Clinical presentation, including symptoms such as abdominal pain, nausea, and vomiting, can also aid in diagnosis
• Laboratory testing, such as complete blood count and electrolyte panel, can help evaluate the patient's overall health status and guide treatment decisions 1.

From the Research

Intestinal Endometriosis and Small Bowel Obstruction

• Intestinal endometriosis is a rare condition where endometrial tissue grows outside the uterus, leading to small bowel obstruction 2, 3, 4, 5, 6.
• The rectosigmoid junction is the most common site for intestinal endometriosis, but small bowel involvement, particularly of the ileum, can also occur 2.
• Small bowel obstruction caused by intestinal endometriosis can present acutely, with symptoms such as abdominal pain, nausea, and vomiting 4, 5, 6.
• The condition can be challenging to diagnose preoperatively, but intestinal endometriosis should be included in the differential diagnosis in cases of bowel obstruction in women of childbearing age 3.

Mechanism of Obstruction

• Endometrial tissue can infiltrate the muscularis propria and subserosa layers of the ileum, causing stenosis and obstruction 5, 6.
• The infiltration of endometrial tissue can also cause inflammation and glandular alteration in the mucosa, leading to obstruction 6.
• In some cases, endometrial tissue can also involve nearby lymph nodes, making the prognosis uncertain 5.

Treatment Options

• Conservative treatment may not always be effective in relieving symptoms, and surgical intervention may be necessary to relieve obstruction 2, 3, 5, 6.
• Surgical options include bowel resection, which can be performed through open or laparoscopic surgery 2, 5.
• Advanced imaging techniques, such as computerized tomography, can help diagnose intestinal endometriosis and guide treatment options 2.