JOHN YANG: Endometriosis is a disease that affects one in 10 people with uteruses over the course of their lifetime.

It occurs when tissue similar to the lining of the uterus grows somewhere else in the body, typically on or around reproductive organs.

It can cause debilitating pain and often leads to infertility.

But after symptoms begin, it can take years for doctors to correctly diagnose it.

A new documentary tells the story of several people as they battle endometriosis and fight for more awareness of the disease and for treatment for it.

WOMAN #1: I knew something was weird.

I knew something was wrong.

WOMAN #2: It took me ten doctors to find someone that believed my pain.

WOMAN #3: I thought maybe I'm dying or I have some kind of rare disease.

I go online and find that millions of women are going through exactly what I'm going through.

JOHN YANG: Ali Rogin is back with a conversation with the director of that documentary, Shannon Cohn.

It's part of our continuing coverage of inequities in women's health unequal treatment.

ALI ROGIN: Shannon Cohn, thank you so much for joining us.

Many people may have heard the word endometriosis.

Maybe they know about it.

There is so much that is unknown about this disease.

What are some of the really important things that people should know about it yet?

SHANNON COHN, Director, "Below The Belt": Arguably, endometriosis is the most common, devastating disease that most people have never heard of.

It affects about 200 million people on the planet, yet takes an average of eight doctors and 10 years to diagnose it's the cause of up to 50 percent of infertility in women and puts a burden on society in the U.S. of an estimated $116 billion each year in lost wages, lost productivity, and associated medical costs.

Yet a lot of people have never heard of it.

ALI ROGIN: And in your work, what have you discovered about why it's so widespread and yet so poorly understood?

SHANNON COHN: I mean, where do I start?

There are a lot of things like endometriosis is a perfect, awful storm of so many things that apply across the healthcare spectrum.

Things like menstrual taboos and societal stigma around below the belt.

Women's issues, health issues, gender bias in medicine, racial bias in medicine, financial hurdles to care, and other institutional hurdles to care that we all go through.

All of these things combine together that make it really difficult for even this huge population of people to get the care, first of all, to get diagnosed early, and then to get the care that they need early.

ALI ROGIN: And speaking of that care, there really aren't that many options.

There's a couple of surgeries that are available.

They're extremely radical in some cases.

Often insurance doesn't cover them.

How is it that there are so few options for treatment and even those options can be hard for women to access?

SHANNON COHN: The reason why is mainly because research funding hasn't been there, enough attention hasn't been put on the disease and women's health in general to find the answers that we need to develop treatments that actually work.

A lot of the medications out there that, by the way, only treat symptoms, none of them actually treat the disease, have been around for 30 years.

They've just been repurposed.

And then another issue is that the vast for in the U.S. for example, the vast majority of the 60,000 OB/GYNs in the country, they don't have the skills to perform advanced endometriosis surgery.

If you envision an iceberg and an iceberg is a tumor or the endometriosis in someone's body, do you want someone to go in and kind of laser the top of it or do you want them to actually cut it out because you may not be able to see the whole lesion?

The issue is that the vast majority of the OB/GYNs in the country only know how to burn the top.

They just haven't had that extra skill set.

ALI ROGIN: So let's talk about what it takes to expand the breadth of knowledge, the professionals that do this.

Congress's role in the film, you highlight a family who has made it their mission to lobby the Hill, meet with lawmakers, try to get attention, and federal dollars.

What is Congress doing?

Are they doing enough?

SHANNON COHN: Well, we're definitely getting started in a really robust and meaningful way.

For several years now, we've been working with Senator Elizabeth Warren, and we started working with Senator Orrin Hatch in 2017 because his granddaughter, Emily Hatch, who appears in the film, and her mother, Mary Alice Hatch, had been phenomenal advocates, along with the late Senator Hatch in really pushing endometriosis forward in a meaningful way.

And when Senator Hatch retired in 2019, senator Mitt Romney stepped in his shoes and really pushed it forward alongside with Senator Warren.

ALI ROGIN: You had a screening on Capitol Hill.

Lawmakers were present.

What was the reaction?

SHANNON COHN: It was so wonderful to see lawmakers from both sides of the aisle come together on an issue, especially in today's political climate, to do with women's health and to see them say, what?

It's not a political issue.

This is a human issue.

Every single viewer watching this right now is affected by endometriosis.

Every single one.

Either they have it or they know or love someone who has it.

It's a guaranteed fact.

So, even if you think, oh, what is this weird word?

I don't think I've ever heard of this.

Should I care about this?

You should.

Everyone should.

Because it affects you.

ALI ROGIN: This is the second documentary that you've done on endometriosis.

Why is this form of storytelling such a powerful way to tell these stories?

SHANNON COHN: I think it's the way we affect change in the 21st century.

I always said this old adage, if you can change hearts and minds, you can change policy.

It's true.

We're all human.

You know, we all have hopes and dreams and loves and disappointments.

When you share a human story, even about an issue you're not familiar with, we all, you know, identify with that.

We identify with that common humanity.

And then, by extension, you start caring about the issues that these subjects in the film go through.

That's how we create change, because all of a sudden, you create a worldwide community saying, hey, we need to do something about this.

This isn't fair.

So that's the power of storytelling.

ALI ROGIN: The documentary is "Below The Belt", premiering on PBS.

Shannon Cohn, thank you so much for your time.

SHANNON COHN: Thank you.

It's an honor.