Endometriosis is the second most common gynaecological disorder requiring hospital treatment, and an increasing number of women are being diagnosed as having the condition. This may, however, be due to technical advancement in diagnostic techniques, particularly laparoscopy, rather than an increasing incidence of the disease itself.

No one knows what causes endometriosis, or how to cure it, and yet medical science continues to throw powerful hormonal drugs with physically and psychologically damaging side effects at it, or perform varying degrees of surgery despite the fact that the problem usually returns when treatment is discontinued. "A single form of therapy with consistent results for all patients is lacking," said the Department of Obstetrics and Gynaecology, University of Tennessee, Memphis (Obstetrics & Gynaecology Clinics of North America, December 1993).

Endometriosis occurs when tissue similar to that of the endometrium (lining of the womb) is found in other parts of the body, usually on the ovaries, tubes and peritoneum. However, deposits have been found all over the body even, in rare instances, on the eye. Adenomyosis is another form of endometriosis found in the muscle of the uterus.

The tissue behaves in the same way as the womb lining, bleeding every time menstruation occurs, causing inflammation and often forming fibrous adhesions which may make organs stick to one another. Infertility may result if the reproductive organs, particularly the fallopian tubes, become inflamed and scarred. However, according to one report, "controlled studies offer strong evidence that endometriosis per se is not a direct cause of infertility" (Annals of Medicine, April 1990).

The most common symptoms are painful ovulation, painful periods and painful intercourse, although there are many others including bloating, heavy or irregular bleeding, constipation and/or diarrhea, constant tiredness, insomnia and depression.

Various theories exist as to what causes endometriosis. The most popular is that, during monthly menstruation, the endometrium not only flows from the womb down the vagina but also back along the fallopian tubes and out over the ovaries, tubes, womb and peritoneum. Sometimes some of this endometrium sticks to the structures in the pelvis and grows as new tissue. This may be normal, to a certain degree, in most women.

An increasing number of women who have not experienced any of the previously mentioned symptoms only discover they have endometrial deposits when undergoing exploratory operations for infertility or other gynecological and abdominal operations. Also the extent of visually diagnosed disease does not necessarily equate with severity of symptoms ie, a woman diagnosed as having mild endometriosis may complain of extreme symptoms, while another with many more endometrial "patches" and adhesions may not experience any symptoms.

This has led Eric J Thomas, Professor of Obstetrics and Gynaecology at the University of Southampton, Princess Anne Hospital, to argue that the presence of ectopic endometrium may, therefore, be normal and should be considered a disease state only if associated with symptoms or signs of progression and tissue damage (British Medical Journal, 16 January 1993).

In three studies following the natural course of the disease without medical treatment, he notes the disease progressed in about half the patients and in the other half either remained the same, improved or disappeared. Increased disease was not necessarily symptomatic. Professor Thomas concluded that "endometriosis should not, therefore, be treated just because it is there".