What is endometriosis in the 1990s?

Intensive research into endometriosis over the last decade has failed to elucidate its aetiology and pathogenesis. There are uncertainties, too, regarding its diagnosis and management. Trends in endometriosis research in this period are reviewed with reference to histopathology, markers, immunology, peritoneal fluid biology, GnRH agonists and bone physiology. The research effort has never been more intense, but much remains to be clarified in the next decade.