"It's a searing pain every time you go to the loo" said Gardner, 60. "It's just like hot needles being inserted inside you and just burning, burning, burning."

She told the BBC she had felt "gaslighted" by medics and had been told to "wipe yourself better" after describing intense pain.

She was even told by one consultant to give up sex because it can cause a flare up.

"You've got to fight all the time just to get treated sensibly and [not told] you've got anxiety, depression or are attention seeking," Gardner said.

The pain and lack of answers about her condition eventually led her to a very dark place.

"It got to the point where [I thought] 'if this is how my life is going to be, I can't carry on'," she said.

She was so desperate she even considered selling her house to pay for private surgery to have her bladder removed.

It was around that time three years ago that she discovered Dr Cat Anderson, a Staffordshire-based GP who works in private practice and for the NHS.

She was the first to identify that Gardner's symptoms were related to the menopause and prescribed her Hormone Replacement Therapy (HRT).

"I had two years free of UTI - I just had my life back," said Gardner.

Asked whether going private went against her Labour principles that healthcare should be free, Gardner said: "You're stuck with a choice aren't you?

"You either suffer or you go private... so I don't judge."

She added that she believed everyone should have access to the healthcare they needed.

Anderson specialises in challenging UTI cases, and is leading a group of medical experts to develop a medical definition of chronic UTIs to differentiate it from other conditions.

The panel hope that an official definition will pave the way for better diagnosis and treatment.

Persistent infections, Anderson said, could "ruin a patient's quality of life" - limiting their ability to work or do something as simple as pick their children up from school.

She has also seen people "who are quite literally driven to suicide" due to "awful" symptoms.