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.

Symptoms of DIE Symptoms include: · Chronic pelvic pain · Menstrual cramps · Infertility · Pain during sex · Painful bowel movements · Pain with urination Occasionally, some patients may have minimal symptoms.

Diagnosis of DIE Vaginal examination may reveal nodules along the back of the uterus. Sometimes bluish nodules may be seen at the upper part (vault) of the back of the vagina.

Imaging techniques using vaginal ultrasound and MRI will outline the size and the extent of the lesion. This is important in the surgical planning before operation.

Treatment of DIE Medical treatment: Progestogen hormones orally or via intrauterine device (Mirena) and GnRH agonist injection may be used to relieve the symptoms. But DIE is unlikely to resolve. There is a high chance of symptoms relapsing after stopping the medicine. Side effects following prolonged medication may not be suitable in patients who wish to conceive as ovulation is being suppressed.

Surgical treatment: As DIE may progress and block the digestive tract, surgical removal of the lesion may be done at some stage. The ideal is a complete resection of all visible lesions whilst preserving pelvic organ function. This may not be achieved in some patients. Assisted reproductive techniques for conception may be required in patients post-surgery.

B was treated medically with oral progestogens for 6 months. The symptoms subsided somewhat as she did not have menses while on the therapy. However, she suffered from side effects like acne, weight gain and mood swings. As the DIE lesion did not decrease in size in subsequent MRI, B requested surgical intervention. This was done laparoscopically with the colorectal surgeon. At the operation, the DIE had encircled more than half of the circumference of the rectum. Part of the rectum had to be resected together with the lesion. The surgery was uneventful and B was discharged well 4 days after operation. She remained pain free at the last review 6 months after surgery.