The saliva test, called Endotest, is already being used in a pilot NHS study, while Endosure – the gut electrical signal test – is part of a clinical study at the Worcestershire Acute NHS Hospital Trust.

Women fast for six to eight hours beforehand and then drink water for 45 minutes during this gut test.

The new draft recommendation means GPs will be able to start offering either or both to some patients, if available. Not every GP will have access immediately and use must be overseen by a healthcare professional with expertise in endometriosis diagnosis and management.

The NHS will continue to gather evidence on how well these tests work.

Neither are designed to act as standalone diagnostic tests but should mean women get a diagnosis and treatment much faster.

Currently, the main way to diagnose whether a patient has the disease on the NHS is through a surgical procedure called a laparoscopy, under general anaesthetic.

Emma Cox, chief executive of Endometriosis UK, welcomed the tests, adding: “Availability of these new tests needs to go hand-in-hand with education of GPs and practice nurses to ensure prompt access to those that need them, and an end to pain and symptoms not being recognised.”