Science Friday - How to poop better, according to a gastroenterologist

Episode Date: April 1, 2026

For many of us, what happens in the bathroom stays in the bathroom: According to a recent survey, 1 in 3 Americans are too embarrassed to talk about their poop or gut issues with their doctor. Gastroenterologists like Trisha Pasricha say that’s a problem, and that that stigma is getting in the way of our health and happiness. She joins Host Flora Lichtman to share some crucial gut knowledge, and talk about her new book, “You’ve Been Pooping All Wrong.” Read an excerpt from “You’ve Been Pooping All Wrong: How To Make Your Bowel Movements A Joy.” Guest: Dr. Trisha Pasricha is a physician-scientist at Beth Israel Deaconess Medical Center and assistant professor of medicine at Harvard Medical School in Cambridge, MA. Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hey, I'm Flor Lixman, and you're listening to Science Friday. First, a content warning. The following conversation will be especially delightful for young audiences. So I'd recommend actually finding nearby children so that they can listen. We asked you to call us about when nature calls. And you know what? I thought we might not get a lot of takers. I was wrong.

I've had plenty of memorable poops in my life. I once had a poop that looked exactly like the number two. It was incredible and too real. Incredible and too real describes many of your stories. I went to the bathroom and there wrapped around my beautiful poo was about an eight-inch long roundworm that I did not know was in my gut. Look, if you're feeling squeamish right now, my next guest says, you're not alone, but that's a problem. Our collective poop shame is getting in the way of our health and happiness. Here to dump some knowledge on us is Dr. Trisha Pusrecha, a neuro-gastroenterologist at Harvard University.

She also writes the ASCA doctor column from the Washington Post and is the author of the new book, You've Been Pooping All Wrong, How to Make Your Bowel Movement, a joy. Tricia, welcome to the show. Thank you so much for having me. Hopefully all I'll be dumping is knowledge, but I appreciate that intro. Okay, Tricia, you write in your book, it's time to give your poop the Cinderella moment it deserves. Do you feel out of sync with society? I think that polite society doesn't think it's appropriate to talk about bowel movements in public. But what I have found as a second-generation gastrologist who talks about poop all the time at work and at home

is that once you crack that door open to talking about it, so to speak. So to speak. And obviously, it's going to be really hard to keep these puns in for the next half hour. But once you do, actually, you open the floodgates. People are desperate to talk about this. And so in a way, yeah, there's this incongruency about what we talk about at brunch or at book club. But people have been waiting for this moment. And I hope that this book makes a little bit of that shame and stigma disappear so that we can talk about it more often. You know, I think our listeners bear that out with their voicemails. But you said second generation gastroenterologist.

So you must have grown up in a poop positive house. First of all, thank you for saying poop positive. I say that all the time. I hope I'm raising a poop positive family too. I have two young kids. But yes, my father was a gastroenterologist. He was actually a neuro gastroenterologist just like me. So we study the gut-brain connection.

And, yeah, I mean, I think I have come to realize that my childhood was a little atypical. But he used to kind of just check in and ask us, did we poop today? Like all the time. Like other dads would ask about, like, well, how was school today? Do you do your homework? He'd be like, so, did you have a bowel movement? What was it like? And I thought that was perfectly normal.

Like, a lot of other parents would ask, like, did you brush your teeth when you came downstairs? My dad would ask about this. And then he'd tell us all about how the gut works and how it was connected to the brain. And he'd talk about colonoscopies that he was doing at work. And we loved it. And it was very easy for me to fall in love with the gut when you hear somebody so excited and passionate about it every day growing up. So it was a real cultural shock for me when I started practicing medicine and I found out that most people don't grow up this way. Most people find this conversation embarrassing, shameful. And also most people are in the dark about how their gut works and even how to poop normally. Well, let's get to that. I mean, let's get to some news we can use. Your book title is, you've been pooping all wrong. How have I been pooping all wrong?

We have not been taught even the basics about pooping. I mean, the last time you probably had a conversation with someone about how to poop was with a parent when you were. were two or three years old when you were potty training. And you probably don't remember. It was 41 years ago. 41 years ago. Thank you. Yeah. And how much of that conversation do you remember? None. None. Yeah. Yeah. And, you know, the fact is that whatever your parents taught you is probably extremely close to what their parents taught them and their parents taught them. So ultimately what you're learning is like your great grandmother's technique. And that is not correct. That's not necessarily congruent with the science that we have today. But we simply aren't going over the basic mechanics with people. And so, you know, just to start, for example, there are several ways that

I think our modern life has really made us poop incorrectly that probably wasn't as big an issue as it was, maybe 100 years ago, great-great-grandmother's time. But one is simply the fact that we bring our smartphones into the bathroom. This is like a huge conversation I have with my patients. And that's because people are increasingly spending minutes and minutes and minutes, dare I say even an hour on end for some people staring at their smartphones scrolling. That changes the dynamics of your pelvic floor. And over time, if you do that, I mean, we did this study in my lab that found that people who bring their smartphones into the bathroom, which we are all doing, let's be honest, they are at a 46% increased risk of developing

hemorrhoids. Why is that? Yeah. Well, I think ultimately what we believe is happening is that it's a time issue, that the smartphones do exactly what they do in the bathroom as they do when we're trying to fall asleep, when we go to the dinner table, which is that it distracts us from the moment and the task at hand. And what we found in our study is that people who take their smartphones into the bathroom were more than five times as likely to spend more than five minutes at a time sitting there scrolling, even though they were no more constipated, not necessarily straining more than the other group who didn't bring their smartphones in. And that really tracks. Like, if I'm sitting there in the bathroom and I start scrolling and I sort of forget why I went in there in the first place, it's very easy for me to get caught into a great episode of the pit.

And then 20 minutes later, I'm like, wait, why did I come in? Oh, that's right. That's right. That's why my pants are down by my ankles. And if you sit in that position in this open bowl without pelvic floor support, I mean, picture the toilet. Your whole pelvic floor is not being supported. Hemorrhoids are just these cushions of veins. And when those cushions start to passively fill, they become engorged, and that's when they become hemorrhoids. And so we think that, yeah, if you scroll on the bowl once or twice in your life, no big deal. But if you make that your pattern, you do that every time you go and you start spending more time in there than you realize, eventually there will be consequences. And we saw that in our study.

Wow. Okay, so you said there are a couple things that we're doing wrong. That's one. Can you give me a few others? Yeah. So, and this one probably doesn't come as a surprise to people, but we just aren't thinking about it as much as we should. in the past, nobody used to sit on these toilets that are like chair-like 90-degree position, right? We used to squat.

And it's true that like the modern, something that looked kind of like a modern chair-like toilet started to show up in the Roman Empire onwards. But if you go even further back in time, we were squatting for tens and tens of thousands of years. And the reason squatting is so important is that if you think about your colon like a tube, a nice long tube, we have this muscle that makes a sling around that tube at the very end. It's called the puborectalis muscle, and it pulls that tube shut, like a, almost like a kink, like your body stepping on its own hose. That's what happens when we're just sitting in a chair.

It's closed shut. Now, that's a good thing when you're sitting in a chair, because you want whatever extra help you can to not keep things from coming out when you're sitting at your desk. However, when you go to the bathroom, you need to straighten that tube out, and the way you can do that is to squat. It's why I have a two-year-old in daycare. If you go to a daycare, you see kids running around in diapers, they will pop the deepest squat of their lives when they're boobing. You know, first of all, they make, like, yeah, painful eye contact with you when they do it, but then they squat. And that's because that is, we know that intuitively when we're young, that that is the

easiest way to get the job done. But we train ourselves against that because we don't have, you know, the physical structure in our bathrooms to do that anymore. Now, I'm not telling anybody they need to start squatting because or go to their, go to their backyard for goodness sake. But if you just raise your knees above the level of your waist, that can be with a stool, it can be with a stack up books, a pair of heels, whatever you want to use, if you raise your knees up, it kind of mimics that relaxation of that muscle and finally your tube straightens out again. But a lot of people have never heard of this concept and are just fighting against them, their own anatomy every time they go to the bathroom.

Let's get to some listener voicemails. You know, we had a lot of burning VMs on BMs. Here's one. Hi, this is Linda from Rochester, New Hampshire. And I have a question. I went to the bathroom at work one day, and someone had forgotten to flush. Their bowel movement was white. I don't understand how that color is possible, and it has always stuck with me.

What do you think, Trisha? Well, first of all, I think there's some poetic. irony to the fact that, I mean, she's been haunted by this white poop for like a long time since she saw it's always stuck with it's always stuck with Linda. But I'm going to tell you two possibilities, right? One, if you see white poop or like clay pale colored poop, that's actually an emergency. You should actually go seek attention. And, you know, this is a surprise to a lot of people, but actually that white pale color, that is the natural color of our poop. We think brown is the natural color. Brown is somehow the amalgamation of everything we've eaten devoid of nutrients.

Not true. The brown comes from something we produce, which is billy Rubin. It's this digestive juice. It's stored in the gallbladder. We secrete it. It gives it the brown color. If we took that Billy Rubin, that bile out, it would be this nice pale white. That's an emergency because it means something's blocking the bile. It could be a gallstone. It could be a cancer. It could be something else. So go to the doctor if you see that. There's one other problem. possibility, though, and I hope that's what happened to our friend here in the work stall, which is that if you ever get an x-ray and you drink barium, barium is a kind of contrast that people drink before medical procedures. I feel like we always forget to warn patients

that that's going to turn your poop white, and then they're shocked the next day. But barium can do that. So you would know this is a very specific situation if you've drunk barium. If that's not you, you should go to the doctor, and I'm talking about emergency room. Are there other colors as a gastroenterologist that worry you? Yes, absolutely. So white is definitely one of them. Anything that can look like blood. So bright red blood, certainly maroon-colored stool.

You will get a pass from me if you've eaten a big beet salad the night before, if you have maroon stool, but that's a just about it. Have you seen that Portlandia sketch, by the way? No. Were there 911 operators? And they're like, were there beats in your salad? Were there? 911, what's your emergency? What have you eaten today?

I had a bowl of soup. At any point, do you think you had any beets? No. Okay, what kind of soup was it? Borsh. Borsh is actually made from beats. So you did have beats. What should I do?

Just flush a couple times. It'll be fine. Have you seen this sketch? Oh my gosh, no. I should see it, though, and I should send it to all my GI fellows. I can tell you there's nothing more disappointing to a GI fellow than to be ready to scope somebody and find out they just had beats the night before. Really? Is that like, you're like, oh, darn it.

You're okay after all. No, I'm just kidding. We're always happy when the patient is okay. So maroon color stool for sure, and then black, black tarry stool. And I'm talking not dark brown. People get real excited for a real dark brown. I'm talking about black like the color of your smartphone screen. And if it's tarry, sticky, that can be what happens when blood mixes with the acid in your stomach. That worries me too. Okay, we had another listener call that gets us into a conversation about AI, anal intelligence. Hello, my name is Paul, and I'm calling from suburban Philadelphia. If someone eats a very spicy burrito and it has a lot of hot, hot, hot, hot, habanero peppers,

as it travels along, is the last stage, the anal nerve, are they going to register some type of defect, something hot or painful? Good question, Paul. Tricia? Paul, you have asked the exact question that won the Nobel Prize in medicine or physiology in 2021. And so let me, yes, so first let me just answer that quickly and say, yes, fiery diarrhea after eating spicy food is something we all have to live. with. And the reason for that is something called the TriPV1 receptor. It's this receptor that is throughout the cells in our gastrointestinal tract. And it is responsible for pain signaling.

What won the Nobel Prize in 2021 was because a group of researchers realized that not only is TriPV1 responsible for pain signaling, but Capsacin, also signals the same receptor. And so when we eat spicy food, it sends this signal up to the brain, like our bodies are on fire, and it starts your colon to start contracting more quickly in your whole intestine. That's why you do get diarrhea. Things start to just move quickly when you eat spicy food. The problem is that we perceive pain differently inside our guts than just on the outside, right? Like things burn our mouth and our tongue. They don't quite burn our stomachs the same way. But just as we get to the exit hatch, there at the end, we start to perceive true pain from those same receptors that on the inside of

our bodies, we don't feel the same way. So that's why people really feel it in the beginning. They feel that pain in their mouth. They feel it at the very end, but usually not so much in the middle. Are there, on the flip side, are there certain foods that are slam dunks for good gut health? Yes. Anything that is high in fiber, your gut thrives on this. And that sounds so simple and so boring because every doctor you've ever met has told you you have to eat more fiber, but somehow the message isn't sticking because 95% of Americans are not meeting their fiber goals. And the reason fiber is so important is actually precisely because we cannot digest it. Fiber travels undigested through your small intestine and makes its way to the bacteria that are

living in your colon, called your microbiome. When they ferment that fiber, they can produce these beneficial compounds that get absorbed into your bloodstream and have these anti-inflammatory effects on your brain, on your heart, even locally on your gut. That's why fiber is so important. It's one of the most important things you can feed your body. We're not doing enough of it because 60% of our foods today come from ultra-process foods, which are notoriously low in fiber. I was going to ask, bloating after dinner, is there an intervention besides unbuttoning your pants? Yeah. I mean, thank God for yoga pants and the pandemic, which normalize that at dinner. But there is actually a quick trick that I tell people, especially in this is big over any holiday weekend, which is to go for a little

fart walk. Okay, the far walk, highly effective way of eliminating bloating. And you might be like, oh, that's just anecdotal. Like, this is not just me saying that. Gastroenterologist researchers have studied this for decades. And what they found is that just going for even a short, brisk walk five, ten minutes soon after eating will help move contents along more quickly and efficiently and people feel less bloated. And they've actually done this kind of related study, which is that I think when I eat a big meal, my instinct is to go lie down and vegetableize on the couch. But it turns out that if you sit up straight, if you can't even go bring yourself to go for the walk, but you just sit up straight on your couch instead of lying down, your intestinal

gas will move 33% more efficiently. So even posture matters sitting up is going to help you more than lying down, even though lying down might feel good in the moment, not as good in the long term. You know, it's funny, Italians have a better, have better branding for this. They call it the Pasajata, but that's exactly what it is. Ooh, what does that mean? The after meal. The after meal. Pasa jata is just like to a passage or like a walk, but it's culturally like a huge part of your day where like you are just expected to take a walk after you eat. Good for that. You have to take a Pasadjata. Yeah. And it also, I mean, it helps with blood sugar regularly. Like, this is a great idea, even if you don't feel gassy.

It helps you after any meal to go for a walk. Okay. Stay with us because when we come back, I want to ask you about the gut-brain connection. Are you down for that? Totally down. Okay. Don't go away. Okay.

You know, you're a neuro-gastroenterologist, which, you know, honestly, was a field. I didn't even know that was sort of like a specific field until reading your book. We often hear about the link between the. gut in the brain and we covered a lot on this show. What are sort of the frontiers of that research that you think are really exciting? Yeah. You know, you're right that in a way it's a new-ish field. It's like really crystallized in the 1990s as a formal field of study, but we have known that the gut in the brain have communicated closely with each other for more than a century. I mean, physicians and surgeons in the past and the 1800s were documenting how stress, how anxiety

seemed to impact how the bowels were moving. But it wasn't really until that more recent time period the 1990s that we started to think about this more than just how the brain is talking to the gut, more about how the gut is influencing the brain. And one big way that these two systems communicate with each other is through the vagus nerve. The vagus nerve is this long, winding nerve that extends down from the brain to almost every other internal organ. Well, it turns out 90% of the signaling through the vagus nerve is actually going in the other direction. It's going from the gut upwards, not the brain downwards. And that really flipped the whole field on its head, so to speak, and made people realize

how many ways have we been missing potentially that the gut is influencing what's driving our thoughts? And it really revolutionized how we think about a lot of different diseases that are not gut health issues, for example. Depression and anxiety, we now know actually can originate in the gut, not the other way around. And one thing that my lab studies, which I think is a really exciting frontier, is Parkinson's disease. And I'm one of the few gastroenterologists in the country who has a grant from the NIH to study Parkinson's, which really strikes people as odd, because I do colonoscopies all day.

And the truth is that we have now gathered enough data to show that probably for a subset of patients with Parkinson's disease, the disease does not start in the head. It starts somewhere else, in the body and the gut is an important area where that could be taking place. If you talk to people who have Parkinson's disease, 80% of them have GI issues. And when I first started practicing... Really? Yeah, a huge number. And when do they show up?

When do those issues show up? They start to show up years, if not decades, before they develop tremors. Before they would ever get diagnosed with Parkinson's, they'll say, yeah, it is weird. I started having trouble swallowing. Or I was completely regular in my whole life. And then in my 40s, my 50s, I suddenly became constipated. I couldn't figure it out. And they've done these studies that show getting new constipation is actually predictive of

later on getting Parkinson's disease. Now, nobody should panic because in America, we're all constipated. But if you combine that with some of these other risk factors, it starts to paint a concerning picture. And what we believe now is happening is that in Parkinson's disease, the hallmark is this protein called alpha synuclein which misfolds. And it's implicated in why the dopamine neurons in our brain. die. Well, it turns out if you do autopsies of patients who have Parkinson's disease, their guts are

riddled with misfolded alpha synuclion protein. And what we think happens is some trigger occurs. Maybe it's an infection. Maybe it's something in what you ate. My lab has studied ulcers, stomach ulcers. Something happens. And we believe that it could trigger alpha synuclein protein to start to misfold and then travel up the vagus nerve, up to the brain, in a process that takes years. So it's brewing inside of you, causing GI symptoms well before you're going to start to get the symptoms that will get you a diagnosis of Parkinson's disease. And the reason why this is such a cool frontier is because if you think about it that way, it means there's this several year opportunity in which we could potentially try to diagnose this, catch it early, maybe even one day intervene and stop. Now, we are certainly several years away from being able to do that. But, you know, the pie in the sky here is that we could do a colonoscopy on someone one day or an uprandoscopy and say, look, you've got these signs.

The signs are there. Here's what we need to do to decrease your risk from it ever hitting your brain. That's so fascinating. You know, we've also covered, of course, colorectal cancer on the show. And, you know, it's been in the headlines constantly. Just recently it became the number one cause of cancer related deaths and adults under 50. what's your experience been like in the clinic with colorectal cancer? Yeah.

I've changed how I practice and how I think about it. When I was a medical student, a young person in their 30s comes in with bleeding, cancer would not be really on my mind. I would be thinking about hemorrhoids. I'd be thinking about maybe inflammatory bowel disease of fissure. Today, if somebody comes in with bleeding, I'm thinking about it. It's still not the most common cause of bleeding. still going to be hemorrhoids or something else, but I have to think about it. We all have to

think about it. And in fact, they've done these studies that show that, you know, not only are younger people slower to bring these concerns to their doctor's attention, right? I think when you're younger, you tend to think it has to be a crisis to talk to your doctor about it, and now you couple that with the stigma of being embarrassed about anything related to your bowels, but even doctors too are slow to act and think, okay, maybe we should push a little harder. We should do a colonoscopy, we should look into it. So we've been seeing it more often. I've made more diagnoses in younger people in recent years than I, you know, certainly was ever seeing 10, 15 years ago. And it's been a big wake-up call. And we also know it's difficult to get insurance coverage if you're

under 45 for some of the diagnosis. Yeah. I mean, this is a huge area of discussion, right? So the new age is 45 for someone of average risk. And you can't, it will be covered by insurance for somebody younger, who has concerning symptoms? So for example, if you see bleeding, if you have a new change in your bowel habits, if you have a symptom, it will also get covered, but routine screening under 45 isn't. But the thing that I also tell people is that, you know, first of all, for people age 45 to 50, we're not doing a great job of even screening those people who are eligible, for whom it would be covered anyway, right? Like, it's something like a quarter of people in that age range are actually getting the screening. And there's actually a significant number of

people who are younger than 45, who deserve to get screened earlier because they have a family history. And we don't find out till later until after they get a diagnosis that actually, yeah, their uncle, their grandmother, their grandfather, what they had was colon cancer. And it would have bought them an earlier colonoscopy if only we had dug into that history. So the other thing I tell patients when I meet them for the first time, the ones who are well, you know, maybe what cancer's not we're worried about, is take this opportunity to get to know your family history really well. We need to know not just, oh, yeah, I think my dad had some GI issues. I need to know exactly what the issue was.

I want to know the age that they were diagnosed. Do we know what's causing this uptick? We think it has to do with something in our environment. I mean, I think we were more in the dark 10, 15 years ago than we are today. We still have a lot to learn. But I think there's more and more data consolidating about our environment, specifically our food, and then even more specifically how we're eating when we're young. You know, some of the concerning studies that have been coming out show that it's how we're eating in our adolescence, in our teenage years, that seems to be fueling this rise specifically in these early onset cases.

Like there was a big study that showed that there's a link in sugar-sweetened beverages, like sodas that we're all drinking in our childhoods and how those are linked to these rises and cases. And in the last year, there have been several studies about ultra-processed foods, which we know every generation is eating more and more of. So the pieces are starting to come together. The problem with ultra-processed foods is that not only do they have these chemicals and additives that these translational studies have shown can disrupt the integrity of the lining of your gut and cause inflammation, but it's also about what is not in your food if you're eating mostly ultra-processed foods. And that's fiber. Fiber, again, is so beneficial, very anti-inflammatory. So few of us are getting enough fiber. Okay.

Well, do you have one more piece of parting advice for our? our listeners about gut health. Like, if there's one thing that people should take away that we haven't heard yet, what is it? Well, one statistic that bothers me is that there was a study that found that about one and three people who have GI symptoms are so embarrassed by them that they would avoid talking to their doctor. So my one bit of advice is to talk to your doctor early and often.

Don't wait for that crisis. And something I often tell to kind of reassure patients who come to see me is that you cannot shock me. As a gastroenterologist, I have chosen to do this for a living. And anything you can say, which you think is so embarrassing, so mortifying, you will be the 12th person that day who has told me that. So don't think that you have something that's going to be so uniquely embarrassing that I'm going to ever feel embarrassed by it. Like, I want to hear it. I am here for it. So talk early and often.

Yeah, and you know what? Look, like if the listeners who called us can tell their story to a public radio show that reaches, you know, over 500 stations and millions of people, then you can talk to your doctor. Yeah. Have that one-on-one little chat. Tricia, thank you so much for talking to us today. My pleasure. Thanks for having me. Dr. Trisha Pusricha is a neurogastroenterologist and author of the new book, You've Been Pooping All Wrong. You can read an excerpt from it at sciencefriday.com slash poop. If you thought the contents of this episode passed smoothly and without issue, I would encourage you to give us a rating and review on your favorite podcast platform app.

This episode was produced by D. Peter Schmidt. Thank you for listening. I'm Flor Lichten. There's just, you're so fun to listen to that we're going really, really long. Oh my gosh. I'm enjoying those questions. That first one that was like, I had a number two in the shape of a number two. That's like record breaking. I need pictures or it didn't happen.