The endoscope images show serious lesions and swellings in the esophagus, the organ that connects the mouth and stomach.
They come from a patient in the South American nation of Bolivia. The person drank a toxic substance called chlorine dioxide — an industrial bleach — under the false but increasingly common belief that it wards off COVID-19.
The injuries are a stark example of the damage being wrought in Bolivia by a campaign to legitimize chlorine dioxide, known by its advocates as Miracle Mineral Solution (MMS).
MMS supporters — a loose global network of conspiracy theorists and alternative health advocates — groundlessly claim the substance can treat virtually any illness.
In Bolivia, buckling under a deep political crisis and a severe COVID-19 outbreak, they have achieved their most startling success to date.
The clinical images seen by Business Insider were included in an urgent note shared among Bolivian doctors faced with a surge in patients who damaged their bodies by consuming MMS.
The doctor who took the images describes its effect as "sudden and explosive." They were shared with Business Insider by another medic in Bolivia, who requested anonymity as they were not authorized to make them public.
In Bolivia, using MMS is currently still illegal. But its healthcare infrastructure is weak, making the country vulnerable to quick-fix promises. Despite warnings, the country's legislature recently passed a bill that would authorize its use.
The legislation is in stalemate after Bolivia's president refused to sign it, and could end up before its Supreme Court.
MMS is said to already be in production at university laboratories, ready to be given to COVID-19 patients. And many people are using it anyway.
Across the country, numerous injuries — and one death — have been reported among those who consumed it.
In July there were reports of three people poisoned by the substance in El Alto, and 10 in the city of Cochabamba. In the city of Trinidad, doctors believe a woman's death was caused by consuming the bleach.
A movement born on the fringes of the internet
For years, people promoting MMS worked on the fringes of the internet, coming under increasing pressure in Europe and North America from health authorities, law enforcement agencies, and social media companies.
MMS is not a medical treatment, but a type of bleach mostly used as a disinfectant, or to whiten paper products.
Its use on humans was first pushed by the Genesis II church, a Florida based organization whose leader, Mark Grenon, was recently arrested in Colombia. He was wanted by investigators in the US, who have linked the promotion of MMS to at least seven deaths.
In the US, MMS been the subject of multiple warnings by the Food and Drugs Administration, which says that it has received reports of "severe vomiting, severe diarrhea, life-threatening low blood pressure caused by dehydration and acute liver failure after drinking these products."
Bolivia's own health ministry has warned against taking the substance. In a July advisory it said MMS "puts the health of the population that consumes it, or intends to do so, at serious risk."
Bolivia is one of the Latin American countries hit hardest by the coronavirus, with at least 118,000 cases and 5,200 deaths among its 11 million inhabitants, according to data from Johns Hopkins University.
The region has been an especial focus for MMS advocates, and Bolivia proved especially fertile ground.
Hospitals are buckling under the pressure, and essential equipment such as ventilators are in short supply. Many Bolivians lack medical insurance, or, because of political unrest or poor roads, can't access hospitals.
Kate Centellas, Croft Associate Professor of Anthropology & Latin American Studies at the University of Mississippi, said that the country is in crisis.
She told Business Insider that contributing factors include "panic over the high level of COVID-19 cases in Bolivia, which seem to be understated given the death rate, and already poor infrastructure which had been struggling to be improved."
Jhanisse Vaca Daza is a human rights activist, whose Standing Rivers charity has organised efforts to distribute essential medical supplies to Bolivians who can't afford or access medical treatment.
She, too, said that desperation was driving the spread of medical misinformation.
The self-described expert fueling Bolivia's crisis
Into the chaos has stepped Andreas Kalcker, a German self-described "researcher" with no apparent medical qualifications.
On Facebook, YouTube, Twitter, and in national news reports, he and his allies have claimed, without the backing of medical authorities and on the basis of mostly anecdotal evidence, that chlorine dioxide offers a cheap and accessible solution to COVID-19.
When challenged, he and his associates have portrayed medical authorities as malign actors involved in an imperialist conspiracy to suppress the cure.
Kalcker describes himself on his Instagram profile as "Chief research at Swiss Center for Scientific Research, Innovation and Development."
Business Insider found no mention of such an organization in Switzerland's official records. Kalcker is also not registered as a medical professional in the country.
Last year his book, "Forbidden Health," was banned by Amazon for promoting MMS as a medicine, after an investigation by NBC News.
Irish broadcaster RTÉ reported in 2015 that Kalcker was using a fake certificate bought online to pass himself off as an expert.
On June 29 he was interviewed on Bolivian national TV channel RED Gigavision about MMS. Kalcker attacked the Bolivian health ministry for warning against the bleach, and claimed that it is effective against COVID-19.
In the interview, pictured above, his credentials are never questioned and is treated as a legitimate scientific expert. He is filmed in what appears to be a laboratory, near scientific equipment.
"Through not giving the substances, they're responsible for genocide!" he claims of the Bolivian health ministry.
In an emailed statement to Business Insider, Kalcker said: "There are 1,327 scientific papers about Chlorine Dioxide... Have you studied all of them?? It sure took me a very long time to do that myself...:))"
"Also bear in mind that further censorship of Chlorine Dioxide use will no doubt lead to many more deaths, and all of this will become Genocide. Genocide is a crime with no statute of limitations and all of those responsible for it will eventually be held fully accountable."
With the coronavirus spreading rapidly in Bolivia over the summer, sources have told Business Insider that many ordinary Bolivians were persuaded by groundless claims like Kalcker's.
'There is so much desperation'
Unlike much conventional medicine, MMS is cheap. It soon became readily available through word-of-mouth vendors, sellers on Facebook, and, later, in pharmacies, according to Vaca Daza, the human rights activist.
She said: "There is so much desperation. We see it first-hand because we are often delivering protective equipment and food. We've seen how desperate people are. So having something that it not only cheap, but also accessible seems like the perfect thing you would want to find right now."
Centellas, the academic, said that many Bolivians are unable to access hospitals, so seek other treatments.
She said: "I think we also have to understand relative risks here. If we're already quite sick and you're unable to get into a hospital, or get a test done, maybe bleach may seem somewhat reasonable — at least you're doing something."
Vaca Daza said the result for hospitals is that they are now dealing with injuries from MMS on top of an already-unmanageable volume of COVID-19 patients.
"They are taking it as a preventative measure, are taken to hospital, then get COVID because of the exposure. It makes things worse, and doctors are already overwhelmed."
Kalcker's efforts to promote MMS in Bolivia have been aided by a controversial group of doctors. They are led by La Paz pediatrician Dr Andrea Callisperis, and call themselves the World Coalition for Health and Life, or COMUSAV. Their website features several videos by Kalcker.
In a statement to Business Insider, Callisperis said that she advocated the use of chlorine dioxide to treat COVID-19 because of its "oxygenating action at a mitochondrial level."
David Colquhoun, a professor of pharmacology at University College London and debunker of pseudo-science, described her claim as "just made-up stuff."
"Whatever actions it has at cellular level have nothing to do with whether or not it helps COVID (or autism or whatever the thing is that they're selling it for at the moment). That needs trials in humans," he said.
Callisperis said COMUSAV is "testing everything" because there is "no scientific evidence for any medicine or substance proposed in the world" to treat COVID-19.
In a video posted on YouTube in July and forwarded to Business Insider by an activist in the country, Callisperis described MMS as "a natural cure that taps the ancestral roots of Bolivians."
Nationwide lobbying for MMS
According to Bolivian media reports, COMUSAV has used MMS to treat patients in Oruro, eastern Bolivia, with the backing of local authorities there. It has lobbied Bolivian politicians to legalize the substance.
The Los Tiempos newspaper reported that city lawmakers in La Paz, the nation's capital, cited "expert testimony" from Callisperis and Kalcker as they pushed to legalize the substance.
Callisperis confirmed that Bolivian legislators had consulted COMUSAV about MMS. She said: "They asked us because they aren't seeing their need for answers to this health crisis being met: the public is requesting a response through their legislative representatives."
Callisperis went on to dismiss reports of harm caused by the substance. She claimed that media reports cited by Business Insider were insufficiently rigorous and that COMUSAV would stop promoting MMS if it were shown "conclusive" evidence.
In his statement, Kalcker claimed that COMUSAV's support for chlorine dioxide was compelling evidence in support of its effectiveness.
"In a best case scenario I could perhaps fool or deceive a handful of doctors... But fool over 3,000 doctors? That would be a most incredible achievement, wouldn't it be?" he wrote.
(It is not clear whether COMUSAV has that many members.)
"Please, do begin to wake up from the 'Matrix' we're in, because there are also many journalists dying as well from this, my friend..."
It's not just media reports, but an influential medical organization that has warned that the substance can kill.
La Organización Médico Colegial, a Spanish medical regulator influential across the Spanish-speaking world, has issued a statement rebutting COMUSAV's claims that MMS can be used to treat COVID-19.
It warned in the August 25 statement that, in the doses recommended by COMUSAV and others, it "endangers the health" of patients and produces "adverse effects that can be serious."
Nonetheless, Dr Callisperis and other advocates have found an eager audience among many of Bolivia's lawmakers, who critics say are eager to exploit the country's political turmoil.
Fake medicine meets political chaos
When the coronavirus reached Bolivia, it found a nation already in crisis.
Last November, socialist president Evo Morales stepped down after allegations of electoral fraud, replaced by the caretaker government of conservative Jeanine Áñez until new elections could be held.
Though Morales fell, his Moviemento al Socialismo (MAS) party retained control of both houses of the country's legislature, leading to a political deadlock.
The Áñez administration has struggled to respond to the coronavirus. Her government has been mired in further claims of corruption, specifically over the procurement of hospital ventilators, a scandal which resulted in the arrest of the country's health minister.
The episode, activists told Business Insider, heightened the mistrust ordinary Bolivians have for country's political class.
For Centellas, advocating unproven treatments has become a way of signalling disaffection with political and scientific establishments, just as in the US.
"I think a lot of it now we're seeing with MMS in the US and elsewhere, if you embrace it, it is a way of articulating your rejection of the current political regime and doubt about what they're saying, and doubt about what is actually efficacious or not." she said.
Elections were due in Bolivia in September, but the Áñez government had delayed them until October 18, citing the coronavirus crisis. MAS supporters have taken to the streets in protest, blocking roads and demanding that Áñez step down.
As it seeks to place further pressure on the government, MAS has seized on the so-called miracle cure being used by across Bolivia, in what critics say is a cynical political gambit.
The next step is for Áñez to either sign the bill into law, or veto it. Despite signalling her opposition, so far she has done neither.
Now the Senate's leader is threatening to overrule any veto of the bill, potentially escalating the case to the Bolivian Supreme Court.
Vaca Daza, the activist, believes MAS has set a trap for Añez: by refusing to approve the bill legalizing chlorine dioxide, she will open herself to MAS claims that she is an enemy of the people, denying access to a life-saving drug.
Vaca Daza said: "My hypothesis is that this would not be happening if it was not months before an election. I think they've created a perfect storm so the MAS party can rise to power again. The whole narrative that the MAS party holds is that the executive and opposition are a bunch of elite people who hate the poor people and want them gone."
"So chlorine dioxide, regardless of whether it is effective or not, is a great thing to fit into that narrative because it's cheap, it makes it look like they're defending the people, and obviously the executive has to block it because it's not healthy."
Senate leader Monica Eva Copa of MAS did not respond to a request for comment from Business Insider.
But as the election nears, and self proclaimed health experts and unscrupulous local politicians continue to tout the substance, it is ordinary Bolivians who are paying the price.
For Centellas, the damage has already been done.
"Even if it's officially banned I'm not sure that will change much in terms of the people already using it or who are interested in using it versus the people who think it's dangerous," she said.
Ruqayyah Moynihan contributed reporting to this article.