Endometriosis is a chronic disease that causes excruciating pain during menstruation, and it’s thought that around 2 million women in the UK suffer from the condition. Research shows that women with endometriosis are facing a nine year delay, on average, before being diagnosed. Why does it seem to be such a difficult disease to diagnose? Dr Karen Ballard from the Women's Health Research Unit at the University of Surrey Postgraduate Medical School and Dr Sarah Jarvis, GP and Women's Health Spokesperson for the Royal College of General Practitioners join Jenni to discuss the issues.