The NGO water.org notes that just 18.9% of Papua New Guineans have access to proper toilet facilities. The worst country in the world for the toilet provision is South Sudan (6.7%).
Out of the world's 20 worst countries for this basic amenity, Papua New Guinea is the only country outside of Africa to feature on the list.
Now movie star Matt Damon is trying to improve sanitation in developing countries, one toilet at a time.
Perhaps more commonly heard discussing his latest blockbuster movie than the perils of open defecation, Damon's A-list status is helping shine some light on an issue that affects 2.4 billion people worldwide.
As co-founder of water.org, which promotes access to safe water and sanitation, the actor is providing funding to some of the world's poorest people so they can build toilets.
Not only that, he's also prepared to enrol the services of some of his celebrity friends to promote a cause that's close to his heart.
As Damon says: "More people have access to a cell phone than a toilet."
Almost half the population in developing regions doesn't have access to sanitary facilities, and an estimated 1.1 billion people practice open defecation, meaning they have to relieve themselves in fields, bushes, forests, rivers or streams, roadsides, or other public spaces.
Societies that practice open defecation are putting themselves at risk of cholera, dysentery, hepatitis A and typhoid.
According to water.org, one in 10 people across the world lacks access to safe water - that's more than twice the population of the United States.
Damon discussed the matter in depth at this year's World Economic Forum Annual Meeting in Davos.
It is often women in developing regions who suffer most as a result of poor sanitation. This is because they are usually the ones fetching water.
"It is personal to me, someone with four daughters, as this is an issue that predominantly affects women and girls," said Damon. "Often it is girls that are leaving school early or missing school entirely in order to scavenge for water."
Meanwhile, the issue of open defecation also mainly affects women. Men are more mobile because of their jobs, whereas women often defecate in fields and by the side of roads.
Water.org is working to end open defecation by providing people with the means to gain access to sanitary facilities.
This is achieved with small loans - $187 on average - that provide just enough for a change in local infrastructure to create better access to clean water and sanitation.
The money can be put towards connecting to a water utility or building a latrine.
The loans operate on a "pay-it-forward" system. Once the amount is repaid it simply moves on to the next person.
Around 938,000 WaterCredit loans had been disbursed as of June, with a 99% repayment rate and women have accounted for 93% of borrowers so far.
Damon intends to raise awareness of the issue by engaging the services of his famous contacts.
He explained: "We had an idea of shooting a PSA [public service announcement] at some fabulous Hollywood celebrity's house and I'd ask to use the bathroom and they'd go, ‘Oh, no, we don't have bathrooms - we practice open defecation'."