What is DIE—Deep Infiltrative Endometriosis?

B, 32, had severe endometriosis. She had deep infiltrative endometriosis involving the large intestine or DIE of the bowel.

As a teenager, B had occasional menstrual cramps with a sensation of “heavy pulling in my womb”. This was temporarily relieved with Chinese herbal medication. However, the menstrual discomfort recurred around the age of 28 and was accompanied with abdominal bloating, nausea, constipation, diarrhoea and pain during defecation. She was initially diagnosed as irritable bowel syndrome (IBS) by her family doctor. The gastro-intestinal symptoms improved with medicine but not the menstrual pain. The intensity of the pain gradually increased and was only relieved with painkillers. She had to take frequent leave from work during the first few days of menstruation. She was then referred for gynaecological evaluation.

As B was not married, clinical evaluation had to be done by examination through the anus. This revealed an immobile normal-sized uterus with a tender and nodular mass about 1.5 cm at the space between vagina and rectum behind the uterus (fig 1). Ultrasound examination of the ovaries were normal. MRI of the pelvis confirmed the pelvic mass. Colonoscopy was normal.

DIE of the Bowel DIE of the bowel is a chronic disease and is difficult to diagnose because the symptoms are usually non-specific, often mimicking IBS. Management is also challenging and complex as the lesion is invasive, infiltrating more than 5 millimeters into the tissues surrounding the bowel. This causes extensive scarring (adhesions) among the pelvic organs which are often stuck together (frozen pelvis) with a deranged anatomy.

Bowel endometriosis typically presents as a single nodule, with a diameter larger than 1 cm. It accounts for 5% to 12% of women presenting with endometriosis. The lower part of large intestines (rectum and sigmoid) accounts for up to 90% of all intestinal lesions.