Defined as the presence of endometrial-like tissue outside the endometrial cavity, endometriosis is a common condition. Estimates of 1 in 10 New Zealand girls and women, transgender or non-binary female assigned at birth are expected to have endometriosis in their reproductive years. 

The cause of endometriosis is likely to be multifactorial with genetic and familial factors playing a role. Clinical presentation may be variable with dysmenorrhea, pelvic pain, IBS and fertility issues present, though approximately one third are asymptomatic.