Kendra Pierre-Louis: For Scientific American’s Science Quickly, I’m Kendra Pierre-Louis, in for Rachel Feltman.
You’ve probably been in this situation: you just had a big lunch or a tall carbonated drink, and out of nowhere a burp rises in your throat unbidden.
[CLIP: A person burps loudly.]
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Pierre-Louis: It’s so magnificent you can taste it. If you are someone’s annoying brother, you’ve probably summoned a burp and unleashed it on your sibling’s face at least once.
But Paras Dhama can’t relate to any of that.
Paras Dhama: Because [Laughs] I can’t burp. And for as long as I can remember, I could never burp.
Pierre-Louis: It may sound silly, but it leads to all kinds of discomfort.
Dhama: So my whole chest and stomach, it becomes heavy—it feels like some air is stuck inside. And it becomes so uncomfortable that one time I was driving on a highway, I had to stop my car, get outside, try to vomit on the side of the road in order to get that air out. I just can’t sit or walk or do anything.
Pierre-Louis: This inability to burp—he thought it was a personal failing, like how some people can’t whistle. But what he’s experiencing is actually due to a medical condition that doctors have only recently begun to understand. To learn more we spoke to Robert Bastian, an otolaryngologist and expert in treating this unusual inability to burp.
Hello. Thanks for taking the time to chat with us today.
Robert Bastian: My pleasure.
Pierre-Louis: So we’re here to talk to you—I think in your paper you describe it as retrograde cricopharyngeus dysfunction. Did I say that anywhere near close to accuracy? [Laughs.]
Bastian: Pretty close. That’s very good. Retrograde cricopharyngeus dysfunction [RCPD].
Pierre-Louis: Can you describe what that is in plain English?
Bastian: Sure. If we think of it mechanistically, there is a sphincter, which is a circular muscle. The iris of the eye, it pinches down in response to light. Well, there is a circular muscle, or a sphincter, right at the top of the esophagus, the bottom of the throat—so in most people it’s in the mid- to low neck, behind the lower part of the voice box—and that circular sphincter lives in a state of constant contraction. Counterintuitively, when it’s kind of at rest it’s contracted. All the sphincters of the GI tract sort of stay contracted, except at the moment they’re in use, and then they relax.
So in this case the upper esophageal sphincter relaxes in the antegrade, the forward direction, to allow us to swallow, and then it clamps shut on the back side of the liquid or the food. But it also must relax in the retrograde direction to let us burp or vomit. And so people with retrograde cricopharyngeus dysfunction have normal antegrade function—they swallow; none of them really have any trouble swallowing—but they can’t burp, and some of them can’t vomit. And so you can imagine the distress that that can cause, horrible difficulty.
Pierre-Louis: Yeah, I think kind of intuitively people understand how it might be a problem that you can’t vomit. Many of us have had stomach bugs, and, like, you know, it’s better out than in. But the burping side, I think, was really not intuitive to many of us because we sort of do that unconsciously, I think, and so why is it useful to burp?
Bastian: Well, every human swallow includes a little component of air because the saliva bubbles. If you spit, you’ll see that it’s kind of foamy. Well, each of those little, tiny bubbles, when it gets to the stomach they begin to coalesce, so they don’t stay as foam. They kind of—over time that builds up what’s called a gastric air bubble; it’s normal in everyone to have that little air bubble. But if that bubble gets to be a certain size, then it needs to be vented as burping.
So if you can’t do that and now you feel uncomfortable because you’ve sensed the need to burp, but you can’t—typically, I think what happens is people begin to swallow extra, and they just build up more and more air, to a degree, in some, that is ridiculous; I mean, they just blow themselves up with air. And all of the downstream air that hasn’t been released upwards, it has nowhere to go except, eventually, as flatulence. But in the meantime, on the trip from the place where it should have been burped all the way down to flatulence, all of that in-between area is distressed by this excess air.
Pierre-Louis: It’s, I think, so fascinating that some people can’t do this because, like, we expect babies to burp, you know, and we know that if babies can’t burp, they get a little bit irritated, and, you know, you have to work [Laughs] to get that gas out.
Bastian: Mm-hmm.
Pierre-Louis: And something I’ve been thinking about is: after I drink something like soda, you know, I burp a lot—like, you know, I’ll do that, like, classic belch—but most of the time I feel like we’re kind of unconsciously burping. It’s not, like, a loud release of gas; it’s just something kind of in the background. How does someone know that they can’t burp versus maybe they’re more of a, like, a tiny burper, I guess [Laughs] is what I would call it?
Bastian: Well, the majority of human burps are silent. Probably in the last week you were around 20 or 30 or 40 burps within five feet, and you knew nothing about it. If you ask people how much they burp, they will tend to minimize the number per day, simply because they stop paying any attention.
So people who can’t burp, how do they know? They know because of the discomfort. They feel the rise of the air, and they say it needs to come out, but they can’t get it out. Some of them have little micro burps on a very occasional basis, once or twice a week or even a few times per year, but they’re unexpected. They’re unharnessable. They’re non-relieving. But then there are other people who absolutely never burp—they cannot remember a single time in their entire lives.
Pierre-Louis: Is there, like, a test for burping? I know that’s a weird sentence. [Laughs.]
Bastian: Well, yes, the single test that would prove that a person can’t burp is called manometry. But if you do standard manometry, as it’s done routinely thousands of times around the world, it will not make the diagnosis.
So the real answer to your question is: no, there is no test needed. What you need is to establish what we call the syndrome ’cause there’s a constellation of symptoms that make the diagnosis in a very firm way. And so basically you ask the patient, and the symptoms that they give you are highly, highly diagnostic: “I can’t burp.” Probably 90 percent say, “I make gurgling noises.” They can be quiet and internal …
Pierre-Louis: Mm-hmm.
Bastian: But more often they’re heard somewhere between a couple of feet away and across a large room. Bloating, and bloating is mostly thought of as an abdominal term, a feeling of pressure in the abdomen, which is the most universal, but often in the chest and even in the low neck. So can’t burp, gurgling, bloating, flatulence—world-class, gold-medal, unbelievable kind of flatulence.
Now, those are the big four, but there are quite a few less universal but still very common: painful hiccups. There’s a hypersalivation issue. When they begin to feel uncomfortable they say, they—their mouths water; that’s quite common. There is a feeling of shortness of breath. There is nausea after eating; that’s a common one. Emetophobia, fear of vomiting, is very, very common. And constipation, even, is one.
So when you talk to patients, and you get enough of those symptoms together, and you combine it with the primary issue—“I can’t burp”—and your diagnostic accuracy is practically 100 percent.
Pierre-Louis: And this is a relatively new diagnosis, right?
Bastian: Yes, well, the index patient for me was in 2015, and the caseload trickled in at first. And so I thought to myself, “For goodness’ sakes, this—somebody knows about this. I better look it up.” So I looked up the English literature; I could find no description. I found individual case reports. For example, one was: combination of can’t burp and chest pain. But it didn’t describe the whole syndrome. Nobody had put it together, and there was no treatment.
And so I was privileged to be the one to codify—by codify, I mean drawing it all together and creating the complete picture, rather than stabbing at “can’t burp” and adding one additional symptom. The full-orbed description of RCPD came from me and was first published in 2019, so really, RCPD became known to the medical community. That’s when the stake was put in the ground.
Pierre-Louis: And do we know if people are born this way, or does this condition, like, develop over time?
Bastian: When you talk to people with RCPD there are many who don’t have information about their infancy. But of the group that knows, that is able to get any information, we’ve learned that approximately one out of three had notable inability to burp as infants; two outta three did burp. Out of the two outta three who did burp there were some who had colic and were gassy and things like that, so there may have been some insufficient burpers. But definitely, there is a group that can’t burp as babies as well.
And in that one third there’s a subset where it was an ordeal for the parents, where they said, “We were taking them to the doctor. We were changing up the formula. We were up all night. He was crying.” One parent said, “Yes, we would measure what we fed her, and we’d cover ourselves with a towel and stand by with a bowl ’cause it, like clockwork, about 20 minutes later she would throw up a huge amount, and we needed to know, ‘Was she keeping anything?’ So we measured what went in, and we measured what came out into the bowl.” And we’ve had a number say, “If this child had been our first child, she would’ve been our only child. We would’ve said, ‘Absolutely cannot do that again.’” But that’s a subset.
So when we say the trouble is “lifelong”—that’s the word we apply—what we mean by that is the patient’s memory, where the patient says, “I don’t remember ever burping,” then we say that’s lifelong.
Pierre-Louis: That makes sense. How does someone get treated for this?
Bastian: Well, the way we do it here is very simple: we meet the patient and validate the diagnosis, and then we go straight to Botox.
We go over to a nearby day surgery center. The patient spends about two and a half hours there. And what happens is: while they are completely asleep—so it’s a full general anesthesia, but it’s a very brief one—we go through the mouth, kind of like a sword-swallowing approach, with a hollow, lighted tube. And you can go down into the upper esophagus. You can find the ridge; it’s like a band. And then you use a tiny needle, and you inject that muscle in two or three places. And then the patient wakes up. They don’t need pain medicine, except rarely. It’s just a little scratchy sore throat. They leave. And then within a few days they begin to burp. That’s one method.
The second method is the EMG-guided. So in that method we do a little bit of numbing. Then we attach some little electrodes, like EKG pads, and then we use a hollow—a Teflon-coated needle and come in from the side and/or from the front; there are two basic approaches to the muscle. And so the patient is sitting in a chair like this with a headrest, and I inject from the side, and then they go home.
Pierre-Louis: And what does the Botox do, exactly?
Bastian: Botox, it causes a chemical paralysis of muscle. When muscle is innervated the nerve endings come in, and they have to be planted into the fibers of the muscle. And it’s that junction—it’s called the neuromuscular junction—Botox goes into that neuromuscular junction, and now that spark of electricity can’t jump across from the nerve to the muscle, so the muscle goes limp. So it’s a chemical denervation that is temporary, lasting three to five months. So now this sphincter muscle, which has refused to relax in the retrograde direction—it clamps; it won’t let go—now it’s become limp, and so the burp can get out and vomiting can happen or whatever.
During the time that the muscle is limped from the Botox the patient then experiences maybe 1,000 burps—micro burps, big burps, in-between burps—and they commune with those burps. They get very mindful about the series of sensations. And they look for what I call the gesture, or the fidget. If you are a burper, you know that just at the moment that you burp you do something to let it go, and that’s what patients have to learn. And so sometimes it’s a head turn; sometimes it’s a chin tuck. But the common one, the one that I’m looking for, is—it’s a lowering the larynx, so the burp is arriving, they feel it arriving, and they kind of [Lowers voice], you know, like, when you talk like Yogi Bear …
Pierre-Louis: Yeah. [Laughs.]
Bastian: You sound like that, or when you’re yawning [Imitates a yawn] …
Pierre-Louis: Mm-hmm.
Bastian: You know, your voice does that kind of a thing when you’re yawning. It’s that sort of a movement.
And then the idea is we have pure Botox burps, and then Botox is fading, so it’s a training wheels kind of idea.
Pierre-Louis: Oh, that’s interesting. So in theory they don’t need to continue doing it. It’s sort of training the muscle on how to burp.
Bastian: That’s correct.
Pierre-Louis: And I guess the last question that I have is, like, patients who have—who, like, undergo the Botox or gain the ability to burp, how do they, like, react?
Bastian: I was fascinated by the number of people who came up with the word “life-changing.” People say things like, “I simply can’t believe that this is what other people are like.” Or they’ll say, “I knew this was bad, but I didn’t realize how bad it was until I got rid of it, and it’s, like, unbelievable.” They’re very ecstatic about the improvement in their quality of life.
RCPD untreated, the way I describe it is severe daily misery. I have patients—I had one who said to me, “Doctor, if I eat lunch—it’s summer or winter—I have to go out to my car, put the seat back because I can’t tolerate the discomfort, the pain in my stomach. I can’t tolerate it,” stuff like that. Miserable discomfort of this disorder.
Pierre-Louis: And such a pretty straightforward treatment.
Bastian: Yes.
Pierre-Louis: That’s all for today. Tune in on Friday, when we’ll dive into potential changes in how we define and diagnose mental health conditions.
But before you go we’d like to ask you for help for a future episode—it’s about kissing. Tell us about your most memorable kiss. What made it special? How did it feel? Record a voice memo on your phone or computer, and send it over to ScienceQuickly@sciam.com. Be sure to include your name and where you’re from.
Science Quickly is produced by me, Kendra Pierre-Louis, along with Fonda Mwangi, Sushmita Pathak and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.
For Scientific American, this is Kendra Pierre-Louis. Have a great rest of your week!