Updated 13th March 2023

The ultimate guide to constipation

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    The formal definition of constipation is having fewer than three bowel movements a week. But did you know that you can have a bowel movement every day and still be constipated?

    Recent data have shown that a quarter of people worldwide have reported symptoms at some point, suggesting that there’s much more to constipation than simply infrequent bowel movements.

    In today’s short-ish episode of ZOE Science & Nutrition, Jonathan and Will dispel some misconceptions about constipation and empower you to have better bowel movements.

    Referenced in today’s episode: 

    If you want to uncover the right foods for your body, head to joinzoe.com/podcast and get 10% off your personalized nutrition program.

    Follow ZOE on Instagram.

    This podcast was produced by Fascinate Productions.

    ZOE Science & Nutrition

    Join us on a journey of scientific discovery.


    [00:00:00] Jonathan Wolf: Hello and welcome to ZOE Shorts, the bite-sized podcast where we discuss one topic around science and nutrition. I'm Jonathan Wolf, and today I'm joined by Dr. Will Bulsiewicz, and today's subject is constipation.

    [00:00:18] Will Bulsiewicz: You probably think constipation is simply infrequent bowel movements, however, it may surprise some people to hear that you could have a bowel movement every day and still be constipated.

    [00:00:27] Jonathan Wolf: What? That's crazy. Are you telling me that everything we know about constipation is wrong?

    [00:00:34] Will Bulsiewicz: Well, Jonathan, maybe not everything, but constipation is about so much more than just how often we poop. I think we can dispel some of the misconceptions about constipation and empower these listeners to better bowel movements.

    [00:00:47] Jonathan Wolf: Well, let's not be really slow to get to the punchline. So let's get into it. Before we start, I think we do need to be clear, like what is the gold standard for how often you should be going to the toilet? From some of the research that I've looked at, I can see that medical professionals suggest anything from three times each day to three times each week can be considered healthy, which is an enormous range.

    So Will, before we go any further, what is a healthy frequency and what is therefore the textbook definition of constipation.

    [00:01:23] Will Bulsiewicz: The formal definition, just to be clear for constipation, is having fewer than three bowel movements per week. Now, let me just say as a gastroenterologist, I actually find this definition to be too narrow and simple. It doesn't cover all the forms of constipation that I've seen in the clinic.

    Constipation is incredibly common, and there's been some recent data that suggests that a quarter of people worldwide have at one point reported constipation symptoms.

    [00:01:49] Jonathan Wolf: Now I just want to reassure anyone listening that Will isn’t just a rogue gastroenterologist off to redefine this whole thing on his own and sort of expand the definition of the problem so he can find lots more patients who didn't even realize they needed him. A team at our King's College London published a paper in 2019 that said a new definition for constipation is needed.

    And I took a look at this and it says they found that the public's understanding of constipation differs dramatically from that of doctors and other medical professionals.

    [00:02:22] Will Bulsiewicz: Yeah, and I think that this disconnect is problematic. Basically, you are disrupting the relationship between the patient and the doctor, and this ultimately will lead to low satisfaction rates. In fact, they found that almost half of the patients who have these constipation issues say that they aren't satisfied with the treatment that they're receiving for those issues.

    And you know, further, the survey conducted by Kings College, that actually indicated that a third of the patients, they weren't even able to recognize the signs of their own constipation when they were describing their symptoms. They didn't even make the connection between their symptoms and constipation.

    [00:02:54] Jonathan Wolf: You know, I find that really interesting cuz when I think of constipation, I think it's really simple. I have a very simple image in my mind of spending a long time on the toilet, probably unable to pass, you know, a stool, a poop at all. So that's what it would mean to me. Maybe combined with the feeling of not being able to go at all, you know, at other times during the day.

    So maybe, normally I am going every day, but now I'm on the third day of my holiday and you know, nothing's happened. Or like, I'm going and I can't sort of fully empty myself.

    [00:03:28] Will Bulsiewicz: And I would say honestly, that you just summarized many of the forms of constipation that can exist that don't necessarily meet into this definition of less than three bowel movements per week. Those are absolutely signs to look for Jonathan. And it could also even include, believe it or not, the idea of not feeling the desire to go, or not even feeling the instinct like, ‘Hey, I have this urge. I feel like I have to go.’

    [00:03:55] Jonathan Wolf: So look, none of this sounds like fun, and I think many of us listening have experienced some of those symptoms at some point, even if they're only rare, or other people, this is something they're living with all the time. Now, I remember from some of our previous podcast, Will, that gas and bloating can be linked to lots of different issues related to our gut.

    So is constipation one of those?

    [00:04:18] Will Bulsiewicz: Absolutely Jonathan, and I think this is one of the important points that I want to get across to the listeners at home. That gas and bloating is one of the telltale signs of constipation. Almost a hundred percent of people who are constipated will experience gas and bloating. But there are also some other symptoms that people could be on the lookout for.

    And this would include the distended or protuberant belly, like, you know, men who look like they're pregnant, something like that. Nausea, loss of appetite, fullness after meals. People often will have a crampy abdominal pain and that, discomfort can actually come in waves, and it can be extremely intense.

    Like, some of these people think it's so intense that they have some sort of surgical issue, when in fact it's just constipation. And you know, the other thing too is fatigue. So this can be another common symptom of constipation.

    [00:05:09] Jonathan Wolf: And so if we are looking at all those problems, how do you actually diagnose constipation? It sounds like it's such a sort of broad mix of things.

    [00:05:16] Will Bulsiewicz: It is a broad mix of symptoms. But you know, the first step is that you have to prove that the person is actually retaining stool. and backing up. And the perhaps easiest way to do this is with an imaging test. So this could be an X-ray or a CAT scan, or there's a test called a Sitz marker study. But the important point is that even though you can demonstrate that a person has constipation with these tests, you can't prove what the cause of the constipation is based upon that test alone.

    And so there are many potential causes for constipation beyond just slow movement of the intestines. And over the last two decades or so, we've developed new testing that's pretty impressive and allows us to really get to the heart of understanding these problems.

    [00:06:06] Jonathan Wolf: So Will, tell me about these tests.

    [00:06:8] Will Bulsiewicz: Okay, so first of all, Jonathan is a test called anorectal manometry, and basically this test measures the pressures of the anal sphincter muscles, the sensation that people have in their rectum, and the reflexes that are in play as a part of the pelvic bowl in terms of relaxing and having a good normal bowel movement.

    And so when they do this test anorectal manometry, they will insert a small catheter into the person's bottom, and once that's in there, the patient is guided through a series of exercises that are monitored by a machine. So I'm sure this sounds fantastic.

    [00:06:42] Jonathan Wolf: I was gonna say. Sounds wonderful, Will. I'm sure you have people signing up for this experiment.

    [00:06:47] Will Bulsiewicz: I'm really selling it right now, aren't I?

    So, but you know, I think that the important point though with this is first of all, it's painless. It is not something where people have extreme discomfort. It's done in privacy. And for those who need it, this test can be completely life-changing. So it allows us to understand how your bottom functions and whether or not you can properly squeeze and relax your, not just anal sphincter, but also the pelvic floor muscles.

    So these are very important parts of this.

    [00:07:16] Jonathan Wolf: So it sort of allows you to understand if actually maybe there's something to do with your muscles, so it's got nothing to do with, I don't know, your microbiome or your diet. You know, it could be something completely different is what you're saying.

    [00:07:26] Will Bulsiewicz: Yeah, and these things can affect the microbiome, but the problem that exists is actually in the way that the muscles function so much. Like I could hurt my shoulder Jonathan, and not be able to raise my arm above my head, and the way that I fix that and restore function to the muscle is not by popping a pill, but instead by rehabilitating the muscle.

    The same type of issue can happen at our bottom.

    [00:07:48] Jonathan Wolf: So before going too deep, cuz I could see that we could spend a long time talking about this, that's one interesting area. What was the other test that you talked about?

    [00:07:56] Will Bulsiewicz: Okay, real quick. The second test is called Defecography. Iit's otherwise known as evacuation proc photography. And basically this is a procedure where they use an x-ray machine or an MRI to visualize the rectum and the anal canal during a simulated bowel movement, and to the point here is that this type of test, it's an imaging test that is done during a simulated bowel movement.

    It can reveal abnormalities that exist that would be missed by other tests such as a colonoscopy.

    [00:08:26] Jonathan Wolf: So I think that's amazing. Those are like incredibly high tech tests that I think most people including and I have, never heard of. Nowm I think a lot of listeners are gonna say, well, hang on a minute. That all sounds very expensive and high tech, and surely constipation is just really easily treatable.

    You go down to the pharmacy, you get a fiber supplement, you know, are any of these tests really necessary, Will?

    [00:08:51] Will Bulsiewicz: These tests should not be the first thing you do once you realize that it's constipation. These tests really are reserved for the patient who is failing traditional therapy. And I think that, you know, now may be a good time for us, Jonathan, to kind of explore how I would recommend that my patients approach constipation in the very beginning, starting with the most basic stuff.

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    [00:09:17] Jonathan Wolf: Sounds like a brilliant idea. So basically, come in, you've said, I'm a doctor. You thought it was constipation. Okay, I'm willing to accept its constipation, even if it doesn't quite follow the rule that you're managing three and a half a week, so whatever. And they're like, okay, great, thank you for your definition. Now, could you actually help me to do something about it? What do you say, Will?

    [00:09:38] Will Bulsiewicz: Yeah, and I think from my perspective, you know, it's sort of common for people to head straight to the pharmacy to pick up whatever sort of medication is available to treat their constipation and sadly, in many cases in our healthcare systems, the doctors will recommend these things. But I personally think that we need to start with diet and lifestyle first.

    This should be our first step. And there are simple steps such as increasing our intake of whole plant foods, where by doing that, by increasing our whole plant food intake, we are actually increasing our fiber intake. And when we reduce our ultra-processed food intake in combination with this, we ultimately are guiding ourselves towards a number one more microbiome friendly. Number two, a dietary pattern that can improve the health of our bowel movements, including potentially resolving mild constipation. So I kind of feel like, whoa, whoa, whoa. Let's not jump to the medications first. We may get there.

    [00:10:40] Jonathan Wolf: And one of the things that I've been really struck at looking at all the members who go through the ZOE program and they report back on sort of changes in their health is there's a lot of people who've been reporting significant reduction in constipation. And I'm struck by that because it wasn't something that any of the scientists were talking about as they were working to optimize this guidance.

    So it's a sort of really for me, really unexpected byproduct. All of these people are following these programs personalized to them, focused really on their long-term health. And then they're coming back quite early on in this program saying, well, like, wow, like my constipation has got much better. I guess, are you surprised by that and can you help to explain why that's happening?

    [00:11:22] Will Bulsiewicz: So I was gonna say, I'm actually not that surprised to be totally honest with you. And what's interesting about it is that the ZOE program was developed, using the microbiome and  looking at things like blood sugar, blood fat, were attempting to improve the health of the microbiome. Now, these microbes, they are connected to our bowel movements, to our digestive health, our digestive function, and to all these other facets of human health.

    And so when we, when we develop a program intended to sort of improve the gut health towards blood sugar, blood fat, we're simultaneously improving the health of these microbes in general. And this leads to these benefits that we see that like we can say it was unintended. This is an unintended benefit that a person has better bowel movements and improves their digestive health and reduces their constipation, but this is exactly the way that this is supposed to work, which is that when we enhance the quality of our diet and we enhance the health of our gut, we will see better bowel movements. We will improve constipation.

    We will have less symptoms. That's a beautiful thing.

    [00:12:29] Jonathan Wolf: And Will, I'd actually like to circle back to something that you said earlier, cuz you said right at the beginning something that blew my mind, which is you can go to the toilet every day and still be constipated, which is, I'm like, well, no. So can you explain, what's going on there?

    [00:12:46] Will Bulsiewicz: Yeah, so I've had so many patients that I literally have to frame this to them like, I need you to trust me on this. Let me explain the whole thing before you tell me that I'm wrong, because it's hard for people to believe that they could poop every day and still be constipated, and in fact, there are many examples of how this can work.

    So I just wanna kind of go through a couple of the patterns, if that's okay.

    [00:13:05] Jonathan Wolf: Of course.

    [00:13:06] Will Bulsiewicz: So, you know, one of the issues is it could be that there's incomplete evacuations. Like when you go, you're not really emptying. Sometimes the way that this works is that you're passing these little small nuggets, and ultimately these people, because they're not completely emptying, they're backing up.

    There's even some people who actually have diarrhea, believe it or not.

    [00:13:28] Jonathan Wolf: And seriously that seems counterintuitive because, you know, I think about diarrhea as like really emptying everything else. So how can you have constipation and diarrhea at the same time?

    [00:13:40] Will Bulsiewicz: Yeah, so, I mean, it seems like they're diametrically opposed and they're not supposed to be connected in any way. So it's gonna surprise some people. But believe it or not, severe constipation can actually manifest with diarrhea. And what we actually call this, Jonathan, is overflow diarrhea.

    [00:13:56] Jonathan Wolf: And by the way, we should have said right at the beginning, we really hope you're not listening to this podcast while you're eating,  I should have put a trigger warning on at the beginning. So tell us about overflow diarrhea for any of our listeners who are still with us at this point, Will.

    [00:14:07] Will Bulsiewicz: Yeah, so as I've said before, and I'll say it again, I'm far too comfortable talking about these things. I could do it all day.  If you take this person who has overflow diarrhea and you were to perform an X-ray and take a look inside what's happening inside their body, what you would actually see is that they are severely constipated and they have a hard calm of stool.

    This calm of stool is actually backing up. It's stuck.

    [00:14:30] Jonathan Wolf: So it's sort of like a log jam in the colon? Is that what you're saying?

    [00:14:34] Will Bulsiewicz: Yeah. For lack of a better expression, there's a log jam. And basically the solid stuff starts backing up. And then the liquid is the part that actually can sneak through. It gets through the cracks and the crevices, and it comes and descends down to your bottom. And then unfortunately, it explodes out as diarrhea.

    So, you know, naturally the inclination for this person who just experienced explosive diarrhea, their inclination is to treat this with anti-diarrhea medicine, which makes it worse. And that's because the problem is not diarrhea, it's severe constipation.

    [00:15:07] Jonathan Wolf: Amazing. And I think I'm sure have a whole discussion about, you know, diarrhea and things like this at another point. So, you know, Will, I know you could speak about constipation for hours, but I think since we'd like to have a regular movement. I guess we don't want to be slowed down and backed up on this topic for too long.

    That's my better attempt at a constipation joke. So…

    [00:15:27] Will Bulsiewicz: Well done.

    [00:15:28] Jonathan Wolf:  Thank you. I am not sure I've managed it yet, but I'll keep working on it. So, you know, if you'd be listening to this and you're in that amazing quarter of the world's population that has constipation from time to time, and you could give our listeners like a few key takeaways from what is designed to be a short podcast, what would you like to tell them at the end of this?

    [00:15:50] Will Bulsiewicz: First thing you have to do is ask the question, is this constipation? If you suffer with digestive symptoms and any change in bowel habits. Ask yourself the question, is this constipation? And open your mind to the possibility that you could poop every day and be constipated. That you could have diarrhea and be constipated.

    Once you answer that question, step one, start with diet. Move towards a more whole foods high fiber diet with less ultra-processed foods. These improvements in dietary quality, as we discuss Jonathan, and as we've seen in the ZOE users many times, will lead to improvements in constipation and more broadly, improvements in your bowel movements.

    Now when we're doing this, couple easy things that you can do. Low hanging fruit. Drink more water, stay hydrated, and move your body. When you move, your bowels will move. Anything as simple as just taking a walk through your neighborhood is more than acceptable.

    [00:16:40] Jonathan Wolf: So it's not like you have to go and do some massive exercise. You are actually just saying like, walk around more.

    [00:16:47] Will Bulsiewicz: I'm just saying get off the couch, like just let's start with the basics and let's just move your body around.

    Now there are some specific foods that I want to just kind of do a quick tip of the cap to, because these specific foods we have found to be beneficial for constipation, and this includes kiwi fruit, prunes, figs, chia seeds, and flax seeds.

    [00:17:07] Jonathan Wolf: Will I have to ask a question about this because again, I'm thinking about my three year old who is maybe not as regular as she should be. She's luckily a bit too young to be embarrassed by this conversation on the podcast, and prune does seem to be quite magical. I'm guessing that is more than just because it's a high fiber food.

    What is going on with something like that?

    [00:17:27] Will Bulsiewicz: Yeah, so even believe or not not prune juice, which many people have heard this trick, and actually I use this with my seven month old Jonathan, so we're cut from the same cloth as dads in some of the stuff we're dealing with. So, Prune Juice works pretty well, and we think that this is partially the fiber content, but also that prunes contains specific ingredients such as sorbitol and the sorbitol helps to draw water into the intestines, and that water helps to lubricate the stool and sort of keep it moving through.

    [00:17:53] Jonathan Wolf: So this is just another example of how food is packed with all of these different chemicals that really have an impact on our bod beyond just calories and raw numbers of fiber and carbohydrate? Is that what you're saying there? This is really is like a very particular sort of medicinal properties.

    [00:18:10] Will Bulsiewicz: Absolutely. But the beautiful thing is that you can be eating these prunes and they, I mean, honestly I think they taste very good, but even beyond that, it's more than just whether or not you poop. There's more benefit to your health beyond that. So I think, you know, those are some of the things that I think about, and the reasons why I say that we should opt for our diet first, because, you know, don't try to out supplement a bad diet.

    I just don't think that that's a strategy that's going to win. Instead, let's optimize diet first, and then if there is a requirement for supplements, then we can add that on the back end. But you know, Jonathan, beyond sort of that sort of conversation, the last point that I wanna drive home to the listeners is that if you are struggling to have a good bowel movement and you've tried these things and you've worked with your doctor, that's where these tests, the anorectal manometry and the defecography, that's where they come in.

    They can be extremely helpful and life-changing for people, in terms of guiding therapy.

    [00:18:55] Jonathan Wolf: And I guess we didn't say this explicitly, but we should do that, of course. And you say this often, Will, right? Like all of these conversations are things that you should be having together with your doctor and making sure as always that you know you're treating the right thing and there isn't something more serious.

    [00:19:14] Will Bulsiewicz: 110% we're here to empower people. We're hoping, you know, my hope of course, is that the listener takes some of this information and that it's important and transformative for them, but that's of course, with the assistance of their healthcare provider.

    [00:19:26] Jonathan Wolf: Brilliant. Well, I think I learned a great deal, including that I don't even understand what constipation is, which is always a great start to learning more. Will, thank you so much.

    If you have listened to this conversation — maybe you are interested in dealing with constipation and maybe you're just interested in your health — then think about trying ZOE’s personalized nutrition program. You can get 10% off by going to joinzoe.com/podcast.

    I'm Jonathan Wolf.

    [00:19:54] Will Bulsiewicz: And I'm Dr. Will B.

    [00:19:56] Jonathan Wolf: Join us next week for another ZOE Podcast.

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