Key Moment: 10 Things Your Poo Says About Your Health: The No.1 Poo & Gut Scientist

In this moment, the gastroenterologist and gut health expert Dr Will Bulsiewicz breaks down everything you need to know about how your poo is one of the biggest signs of your overall health. Will says that too often we see poo as disgusting rather than a major clue of our health, as he says poo for a gastroenterologist is what checking the pulse is for a cardiologist. He says that signs can range from the size, smell and shape of poo, all of which can indicate anything from a poor diet to colon cancer. This is because 60% of your poo is bacteria and a direct window into the state of your microbiome which impacts all areas of your mental and physical wellbeing. Listen to the full episode here - Spotify-https://g2ul0.app.link//D9d8Wb9r1Pb Apple - https://g2ul0.app.link//vyoc8p5r1Pb Watch the Episodes On Youtube - https://www.youtube.com/c/%20TheDiaryOfACEO/videos Will: https://theplantfedgut.com/ Learn more about your ad choices. Visit megaphone.fm/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:03Steven Bartlett?

  I read in your book that 60% of poop is bacteria.

• 0:07Dr. Will Bulsiewicz?

  Yeah.

• 0:07Steven Bartlett?

  Which just blew my mind.

• 0:09Dr. Will Bulsiewicz?

  Yeah, and I think that this is an important conversation to have because we have stigmatized poop. We're not allowed to look in the bowl. We should be looking in the bowl. And the reason why is because if I were a cardiologist, I would come over and I would check your pulse. I would listen to your heart and those vital signs would allow me to have an idea of how you're doing in terms of like just on a basic level, your cardiovascular health. All right, I'm a gastroenterologist. If I want to know the basics of what's going on with you and your body, I need to know how you're pooping.

• 0:42Steven Bartlett?

  So let's close off on this subject of poop.

• 0:45Steven Bartlett?

  My team actually prepared some poop samples earlier on because I was wondering, as a gastroenterologist, I wondered that if you could look at someone's poop and determine whether they have good gut health and if you can understand what's going on in their body just by how their poop looks. Because poop comes in many shapes and sizes. So what I have here is a variety of different shapes and sizes of poop.

• 1:09Dr. Will Bulsiewicz?

  Yeah.

• 1:10Steven Bartlett?

  For anyone that can't see, well, look at the screen if you're listening to this podcast on Spotify or YouTube.

• 1:16Steven Bartlett?

  Different shapes and sizes of poop here. This is real human poop.

• 1:21Steven Bartlett?

  So I'm passing you that so you can play around with it.

• 1:23Dr. Will Bulsiewicz?

  Yeah.

• 1:26Steven Bartlett?

  And why does the shape and size of our poop tell us anything? Why does it matter? And how is it indicating something that's pertinent to our overall health?

• 1:32Dr. Will Bulsiewicz?

  Well, because it goes back to what you mentioned earlier, which is that 60% of our, 60% of the weight of our stool is actually microbial in origin. So if you want a window into your microbiome, look at your poop. You don't necessarily need to go and do an expensive test. Quite simply, looking at your poop is one of the ways that you can tell what's going on. So there was a study that was done in the 90s, a long time ago. And it was less than 2,000 people exclusively in the city of Bristol. And it led to the creation of a chart called the Bristol stool scale.

• 2:05Steven Bartlett?

  About here, I'll put it on the screen.

• 2:07Dr. Will Bulsiewicz?

  Yeah, and we're gonna, we're gonna run through this, but before we do, I want to mention a few things real quick. As the US Medical Director of Zoe, I'm proud of my contribution as a gastroenterologist, as a physician, to the work that we're doing there. And we not only did the Blue Poo Study, which we've talked about already, which is that you can eat your muffins and figure out your gut transit time, but we also did a couple of other things. One is called the Blue Poo Challenge, where we had over 20,000 people across the planet who were basically eating blue muffins and then reporting back to us on what was going on with them. And then more recently, so again, the Bristol Study was 2,000 people exclusively in the city of Bristol.

• 2:48Dr. Will Bulsiewicz?

  We recently did the largest study across the entire UK on poop and what people were doing in terms of their bowel movements. So it was called the Big Poo Review, and we had 142,000 people from across the UK basically fill out a 17-question survey. And part of what we were looking at was their Bristol stool form. We were also looking at how often they poop. By the way, the average person poops 1.7 times per day. And we were also looking at like how it associates with different conditions. So as an example, 1 in 5 people in the UK are constipated. 1 in 6 people in the UK have diarrhea. So it's interesting to take a look at all these things.

• 3:27Dr. Will Bulsiewicz?

  So now getting into the Bristol stool chart, the dream.

• 3:34Steven Bartlett?

  That is real poop.

• 3:35Dr. Will Bulsiewicz?

  This is, it's lovely. This is the dream. This is where we all want to be. And this is a Bristol 4. The Bristol 4 is the classic, where I come walking out of the bathroom in slow motion, and rock music is jamming, and doves are flying in slow motion, and I just am such a stud. So, and that's after a Bristol 4. My wife knows what happens when I come out looking like that. It's soft and formed, okay? And it's like a sausage or a torpedo. So, pretty smooth. Now, when we move from a 4 to a 3, a 3 is not that big of a deal, but it is getting some cracks and crevices in it. All right, so and we're moving towards constipation.

• 4:19Dr. Will Bulsiewicz?

  Now, a three, you know, a little more fiber, a little more hydration, some exercise. These are simple things that can help to get you back to a four if you're having one of these, a three. But that moves us to a Bristol two, where we are truly getting into constipation territory here. And basically, this is like if you took a whole bunch of marbles of poop and jammed them together. So it still forms into something, but it looks like a pack of marbles of poop that are stuck together. So that's a Bristol two stool, that's constipation. And then finally, a Bristol one is when you're having the rabbit, the rabbit pellets, and they're hard. They're not easy to get out, and sometimes they're a lot bigger than this, this is, these are small.

• 5:01Dr. Will Bulsiewicz?

  So you would, you would form this up into what would be like a golf ball. And that golf ball would be like a Bristol one.

• 5:10Steven Bartlett?

  Okay.

• 5:11Dr. Will Bulsiewicz?

  All right. You form it up into a hard ball like this, but perhaps even bigger. And it's actually hard for a person to pass this. It's so big, it's so hard that your bottom has a problem relaxing to let it out. Okay, so Bristol one and two are forms of constipation. Let's go back to the middle, we're going to start from five. The stool is soft, it's not hard, it's not lumpy bumpy, it's soft. But it's starting to break into blobs, different pieces of poop. So, and we're moving towards, we're moving towards diarrhea where like just like fragments of solid stool

• 5:53Dr. Will Bulsiewicz?

  are Bristol six, and then when it's just like, or the other thing of Bristol six could be like a cow pie. Where there's no form, it's just someone plopped down this formless patty. And a Bristol seven finally is straight liquid.

• 6:12Dr. Will Bulsiewicz?

  Straight liquid.

• 6:13Steven Bartlett?

  And how is this pertinent to our gut microbiome, our health? What does this tell us about our health?

• 6:18Dr. Will Bulsiewicz?

  There's been now multiple studies, including our work at Zoe on the blue poop study that was published in the journal Gut. There's now been multiple studies where basically what they found is that if you can look at which of these Bristol types you have, it does give us some insights into your gut microbiome and what's happening there. So now, where do we want to be? In a perfect world, we want to be somewhere on the spectrum of three, four, or five. We ideally want to be a four. You're not unhealthy if you have a three or a five.

• 6:49Steven Bartlett?

  So if this type four poop, which is kind of like a sausage, it's kind of like a smooth sausage.

• 6:53Dr. Will Bulsiewicz?

  Yeah.

• 6:54Steven Bartlett?

  Is optimal. How does one do that? What is turning it into a type four? What are they eating, doing?

• 7:00Dr. Will Bulsiewicz?

  Yeah. Interesting question. We, one of the things that we found in the Big Poo Review, which is our nationwide survey of 142,000 people, we actually looked at what they were eating. And we were able to find associations between fiber intake and specifically plant-based food intake and having a number four. So in other words, we found associations between fiber intake and basically plant-based food intake and having a number four. So basically what that means is the people that were having a number four bowel movement were consuming more legumes, whole grains, fruits, and vegetables. The people who were having, whether it be a type one or a type seven, they actually were quite similar in terms of their diet, which is that they actually were consuming

• 7:45Dr. Will Bulsiewicz?

  lower amounts of fiber. Now, the other thing to look at too is actually some studies have found that people who have more on the spectrum of constipation tend to have a higher fat diet, tend to typically consume more animal products, which of course are higher in fat. And people that are more on the loose or diarrhea side of things tend to be consuming more plant-based foods. So now you could have a very healthy diet and be having a Bristol five, and that actually is not problematic. And the reason that you're having the Bristol five is because you're consuming so much fiber that actually you're producing a lot of short-chain fatty acids, and those short-chain fatty acids, they're like lubricants for your poop.

• 8:31Steven Bartlett?

  And the gut transition time, how does that relate to these different types of poop? As you're saying that, I was thinking the one in seven, the type one and the type seven, the type one being those sort of hard nuts and the type seven being basically diarrhea. I was assuming that those are the poop types that would happen with a lower and a super high gut transition time.

• 8:51Dr. Will Bulsiewicz?

  That's right. So a slow gut transit time, which is a gut transit time more than 58 hours. So again, and this is all with the blue muffins. You eat the blue muffin, it comes out 58 hours later. You are more likely to be having a Bristol one or Bristol two, which is the classic constipation form. There's no way, no way that you would have slow gut transit time and have a Bristol seven. That's not possible.

• 9:15Steven Bartlett?

  A diarrhea.

• 9:16Dr. Will Bulsiewicz?

  Yeah, diarrhea.

• 9:17Steven Bartlett?

  So diarrhea comes out fast and these sort of hard nuts, they take typically a long time.

• 9:21Dr. Will Bulsiewicz?

  That's right. And the reason why this is happening, you know, so when water moves through the intestines, because a ton of water moves through the intestines and one of the jobs that our colon has, the varicose intestine, is to pull the water out. So the more time that something spends inside the colon, the more it's actually going to do that pull the water out. This is the reason why when we have fast transit, it's high in water. And this is also the reason why when it's slow transit, it's extremely dry.

• 9:52Steven Bartlett?

  Okay. So that's the shape and size of a poop. But what about colors of poop? I've got some different colors of poop here. I've got some reds, some blues, some blacks, some greens, some whites and some yellows.

• 10:01Dr. Will Bulsiewicz?

  Yes.

• 10:02Steven Bartlett?

  How is color pertinent to health and everything we've been discussing?

• 10:06Dr. Will Bulsiewicz?

  All right, let's break this down. So first of all, why is our poop brown? The answer to that question has to do with bile.

• 10:13Dr. Will Bulsiewicz?

  Bile is produced by our liver. It's actually involved heavily in digestion of fat. So when we, for example, eat a fatty meal, our gallbladder will squeeze. People that have gallbladder issues know what I'm talking about. You eat a fatty meal, your gallbladder squeezes. Bile then mixes in your intestines with the food and the bile helps to absorb the fat. That bile is what makes our poop brown. Now that becomes particularly relevant if we're talking about a white poop.

• 10:43Steven Bartlett?

  People poop white?

• 10:44Dr. Will Bulsiewicz?

  Some people poop white.

• 10:46Steven Bartlett?

  No way.

• 10:46Dr. Will Bulsiewicz?

  Yes. And the reason why a person would have a white poop is if there's a blockage that stops the bile from mixing with their intestines.

• 10:58Dr. Will Bulsiewicz?

  On the flip side, if you are struggling to process your fat, you could have a yellow poop. So, and this could be a person who has like a pancreas issue, for example, chronic pancreatitis. And so if they're not able to digest their fat, they have a fatty poop, it may come out yellow. And one of the things that they'll notice is that there may be an oil slick at the top of the toilet bowl.

• 11:22Steven Bartlett?

  Right.

• 11:22Dr. Will Bulsiewicz?

  That's fat, oil is fat. So, all right, you've never had a, have you ever had a green bowel movement?

• 11:27Steven Bartlett?

  None of your business.

• 11:30Dr. Will Bulsiewicz?

  Answer the damn question.

• 11:32Steven Bartlett?

  No, I haven't, no.

• 11:33Dr. Will Bulsiewicz?

  Okay. I have.

• 11:35Steven Bartlett?

  Oh, really?

• 11:36Dr. Will Bulsiewicz?

  Yeah, there's a couple of reasons. Some are healthy, some are not. So you could have, you could have diarrhea like from an infectious cause. An example could be something called Giardia, which is a parasite. And that'll give you a green poop. But you could also go too hard on the smoothies. I was drinking like 40 ounces of green smoothies a day and my poop would come out green. It's interesting. We're gonna, we're about to get into some that are really important. Before I do that, let me just mention real quick the blue. So the blue poo. You could get a blue poo from eating blueberries, particularly if you eat a lot of them. Or alternatively, of course, this is the blue muffin, the blue poo challenge. So, and perhaps what we could do in the show notes is give people the recipe for how they can go about doing that if they, if they're interested.

• 12:21Dr. Will Bulsiewicz?

  All right. Red and black. So we have to talk about, let's, let's start with red. Because of course, red, we think about blood. And, and I have a rule, which is that if you see blood in your stool, that's not normal. And to me, that's grounds to talk to a doctor. And, you know, then there's different levels of intensity of how seriously we check it out. But Stephen, colon cancer, which can present with red stool. Colon cancer is the number two cause of cancer death in our countries.

• 12:57Dr. Will Bulsiewicz?

  In the United States, 150,000 people are diagnosed per year. It's highly preventable. And it's shifting towards younger people. There has been a change in the last few years in terms of colon cancer where, you know, as an example, a person of your generation, you and I are pretty close, I think, but I'm a little bit older. A person of your generation is four times more likely to be diagnosed with rectal cancer during their lifetime than my parents were. And twice, twice times more likely to be diagnosed with colon cancer compared to my parents' generation. So there's been this shift, and it's also affecting younger people.

• 13:41Dr. Will Bulsiewicz?

  So my point is this, I've had patients who come to me, they go, I saw a little bit of blood in my stool, do a colonoscopy and discover that they have a massive polyp, which is a precursor to cancer. And by removing the polyp, we just basically stopped them from developing cancer. So I take it seriously when you see a poop that is coated in red. All right. Now, that red may be just on parts of it, like it is here, where that's typically bright red coming from the bottom. So that would be either something in your rectum, could be hemorrhoids, could be an anal fissure, could also be a polyp in the rectum.

• 14:22Steven Bartlett?

  Okay.

• 14:23Dr. Will Bulsiewicz?

  But I think what I come back to is I would encourage people to get checked out because just seeing the bright red blood doesn't mean it's hemorrhoids, don't assume that, right? Particularly with cancer shifting towards younger people. I think it's important to like get checked out.

• 14:35Steven Bartlett?

  On that point about cancer shifting towards younger people, is that because our diets are changing?

• 14:39Dr. Will Bulsiewicz?

  I think so. I think it's, I think it's, I think it's the shift generationally that's taken place in terms of our diets. I also think that there's a microbiome element. The, the connections between the gut microbiome and colon cancer are as powerful.

• 14:55Dr. Will Bulsiewicz?

  As any type of cancer. And at the same time, what protects us? And I think you know what I'm gonna say. It's the fiber and the short chain fatty acids. And in that study that I was mentioning earlier from Andrew Reynolds, the professor from New Zealand. Actually, there was a powerful association between fiber consumption and protecting ourselves from colorectal cancer so powerful that for every gram, five grams of fiber that we increase in our diet, we are getting a significant reduction in our risk. So it's not just do you eat fiber or not? It's actually how much fiber do you eat? And the more, the better. You know what? I should mention real quick, red stool can also come from eating beets.

• 15:36Dr. Will Bulsiewicz?

  It will almost always happen like literally, you know, 24 to 48 hours after you eat the beets. So don't be surprised when that's the case. You may see a little bit of red stool. Black stool can come from benign places. So an example is bismuth. So like Pepto Bismol. So you have a stomach ache and then you take some Pepto Bismol. And so, but the issue with this is it'll actually give you a black stool. So if you're having a bad stomach for a couple of days in a row, it could turn black. But the other thing that turns your stool black that people need to know about is a slow GI bleed. Bleeding into your stomach specifically. Because that bleeding is happening higher up in your intestines.

• 16:18Dr. Will Bulsiewicz?

  And then it has to pass all the way through like intestinal transit time, right? Because there's such a delay, by the time it gets down to your rectum, it's now black. It's not red anymore. So black stool can be indicative of bleeding. The way that we can differentiate this is when it's blood, it smells terrible.

• 16:37Steven Bartlett?

  Now we've got to start smelling our own poop.

• 16:38Dr. Will Bulsiewicz?

  Yeah, well, you don't have to stick your nose into it. It's so clear, like it will be so clear.

• 16:44Steven Bartlett?

  Okay.

• 16:44Dr. Will Bulsiewicz?

  Okay. When I'm in the hospital, I will be walking through and I can literally tell when a consult is coming because I can smell this diagnosis.

• 16:52Steven Bartlett?

  Really?

• 16:53Dr. Will Bulsiewicz?

  Yeah. So anyway, the stool will turn black. It will smell terrible and it will be like tar. That's what makes it different than if you were to, for example, take Pepto Bismol.