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Bye!

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Hey everybody, it's Mikki here. You're listening to Mini Mikkipedia on a Monday. And today I want to chat about something that nobody loves talking about actually. Unless you're a naturopath or a nutritionist perhaps as well, I have it on very good authority that naturopaths don't mind at all digging really deep into digestion, into bowel motions and things like that. And to be fair, I've had conversations myself, clearly almost on a weekly basis.

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of people trying to suss their digestion out. And in fact, this is what we're talking about today, fixing your constipation, or rather why more fiber and more water might not be fixing your constipation. And this was inspired by a woman in one of my Monday's metadata groups. You know, she's eating one to two kiwi free today, drinking plenty of water, and she's still not able to do number twos. She said she's tried all the supplements.

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that they work for a while, but then they stop working. And she's basically now just working to fund this supplement stack that she's just sort of sitting around in her cupboard at home. And she sort of finished off her post by saying, look, I think the next thing I'm going to try is like a colonic. you know, of course, as nutritionists, we have these conversations a lot. And what struck me about this particular one is that, like a lot of people, she'd

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already done pretty much everything she's ever been told to do. She's up to fiber, she's drinking plenty of water, she's getting in some daily movement, having the kiwi fruit, she's got a shelf of supplements, but she's still stuck, pun intended. So today I wanna chat a little bit around this topic, but instead of telling you to eat more fiber and drink more water, I wanna talk about the three reasons why that advice fails, including one that

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is not that well known, and I want to talk about whether fibre itself could be part of the problem. quick scene setting, if we look at the global prevalence of chronic idiopathic constipation, now idiopathic means no clear cause, it's around 14%, which is not an insignificant number. Women are about twice as likely to have it as men, and it does climb with age. It is also very strongly linked with irritable bowel

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syndrome or IBS. So if you are a woman in your 40s or 50s listening to this and thinking, yeah, this has got worse, well, you're not an outlier. You're pretty much part of that demographic. Now you may be wondering why women more than men? So there has been some studies on this and a few studies have found that the colonic transit of material through the bowel

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It's about 42 hours in women versus 30 in men. That's quite a time difference and actually quite a long time. Another research study by SADEC found that gastric emptying, small bowel and colonic transit were all significantly slower in women. And the largest data set was a wireless motility capsule study of 215 healthy volunteers. And they found that

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Women had a longer gastric emptying time by about 17 minutes, longer colonic transit by 104 minutes, and longer whole gut transit by 263 minutes. So certainly the plumbing does tend to run a bit slower. And it isn't necessarily hormones. This is often the default explanation, but there have been studies looking at transit time in women during both follicular and luteal phases and in men in general.

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twice, matched over that full-week window, and their conclusion was that the influence of the menstrual hormones on transit must be small and probably not of much clinical significance because the within-person variation in men was of a similar magnitude. And that just means that the difference between the men at both time points was pretty similar to the difference in women at both time points. The Mayo Clinic proceedings found pretty much the same thing, that the effect of hormones on

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coal and transit are far less important in humans than in rodents. actually that same review I just mentioned thought that the constipation is more common in women, partly because of defecatory disorders, which caused constipation and more common in women. indeed another community study of over 1300 older adults found that the outlet delay was more frequent in women or functional constipation was associated with advancing age, but not sex.

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One explanation could be childbirth. So there was a survey of 4,000 women that found that 67.5 % had at least one pelvic floor disorder, constipation in 33.2 % and obstructive defecation in 26.8 % with vaginal delivery and higher parity, i.e. more births, both increasing the risk. And this isn't a unique finding because there was a similar study in about

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2600 women finding that constipation was more likely in women who had a vaginal delivery versus those who had a cesarean. And there was a review of over 314 patients referred for chronic constipation and they'd found that 68.2 % of them had a pelvic floor dysfunction and that they were more likely to have had a vaginal delivery, particularly a complicated one, and pelvic organ prolapse.

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So, I mean, it isn't just childbirth, but this plays a large part in this. And in addition to that, there are changes in the pelvic floor with age that affect predominantly women as well. Men's constipation worsens with age because of transit slows, women worsen because of pelvic floor changes. So it's not just transit, it's a lot to do with the changes in that pelvic floor, which

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I thought was super interesting. So I guess this really does point actually to one of the first things I want to raise is that constipation is not just one thing. When someone says that they're constipated, they could be describing at least three completely different problems. The first one is slow transit. So the colon is moving things through too slowly, still sits there, water gets reabsorbed, the stool gets hard. The second one is a normal transit, but with that IBS overlay. So transit's actually fine,

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But there's visceral hypersensitivity, there's bloating, there's discomfort, and there's a feeling that something is wrong. And that is that IBSC territory, C standing for constipation. And the third one is an outlet problem. The transit is fine, still consistency might be fine, but the exit isn't working. And that's one that is often missed. So the thing is, that fiber is a bulking agent. Its whole job is to increase stool volume in a whole water.

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So if the problem is slow transit, adding bulk could definitely help. If the problem is that the outlet isn't opening, adding bulk to the system that can't evacuate is like adding more cars to a motorway with a closed off ramp. You know, it's just not going to work. You get more traffic. You don't get more flow. And this is actually what a lot of people experience. They add fiber. They feel more bloated. They're heavier. They're more uncomfortable, but they're no more regular.

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then they assume that they haven't done enough and they start layering these things on. And of course this might make you think, well, God, is it the fiber that's the problem? So there was this one study by Ho and colleagues in 2012, where 63 people with idiopathic constipation, so no clear cause, they had a colonoscopy to first rule out anything structural. And then everyone was asked to go on a no fiber diet for two weeks. And after that, to settle at whatever fiber intake felt acceptable to them.

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So at six months, you had 41 people stayed on no fiber, 16 were on reduced fiber, and six had gone back to high fiber. The no fiber group went from a bell motion roughly every 3.75 days to one a day. The reduced fiber group went from about one in every 4.2 days to one every 1.9 days, and the high fiber group didn't change at all, still sitting at about one motion every close to seven days or a week.

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Bloating was reported by 0 % of the no-fibre group, 31 % of the reduced group, and 100 % of the high-fibre group. Straining followed the same pattern. Now, the interesting thing was is that it might sound quite dramatic, and I've seen this study before, actually. It wasn't a randomized controlled trial. It wasn't blinded. It's pretty hard to blind something like this. There was no placebo, and people self-selected which group they ended up being in. So the people who stayed off

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fiber with the people that they clearly suited. that is a design that will shift our interpretation of that intervention. And also of course, it is hard to run these trials. Obviously 63 people isn't the biggest trial in the world, but hey, it's better than 12. The other thing with this, which I think is super interesting is this was conducted back in 2012 and it hasn't been replicated, not once in 14 years that I could see.

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There was another group that systematically reviewed foods, drinks, and whole diets in chronic constipation. They found 21 studies and exactly one of them was the no fiber diet and that was the Ho and colleagues study. So I don't know that I could definitively say it's absolutely the fiber that's causing the issue. Clearly this is like one uncontrolled trial. It's a hypothesis more than anything. However, this could be an issue for some people. Now,

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When I went looking at this study, another thing that sort of came out as a suggested issue with it was that everyone did have a colonoscopy to rule out anything structural, which was great, but it wasn't meant to be that anyone had had anorectal testing, which means a decent chunk of that cohort could have had an outlet problem that I'm about to describe in this next section. And again, like I said, if your exit is an opening, then yes, removing the bulk will make you feel better, but fiber was never for the underlying

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pores. that's super interesting. What is actually well supported and is possibly more useful anyway, it's not about how much fiber, it's what type of fiber. So there have been studies looking at fiber types in IBS. Soluble fiber and psyllium husk significantly improved global symptoms with a relative risk of 1.55. In soluble fiber, corn and wheat bran showed no

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significant benefit and in some cases worsened the clinical outcome. There was a 2011 review of chronic idiopathic constipation and they pretty much found the same thing. Soluble fiber improved these global symptoms, straining and still consistency, or the evidence for insoluble fiber was a bit conflicting. And the mechanism, sort of interesting, comes from McElroy and McCowen in the Journal of the Academy of Nutrition and Dietetics and their argument is

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that for fiber to have a laxative effect, it has to survive, has to resist fermentation and still be physically present in your stool at the other end. If your bacteria eat it on the way through, then it's not really there to do its job, is it? This means that soluble fermentable fibers, inulin, a fiber known as phos, fructo-illigosaccharides, not great if you've gotODMAT issues, some fibers can be constipating, specifically wheat dextrin

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and fine, smooth, insoluble wheat bran particles. So, if you are someone taking a daily greens powder for your gut health, inulin and chicory root are the most common fiber types in these products. They are excellent food for your bacteria, they produce gas, and based on this evidence, they are then not laxatives. not going all the way through. Psyllium behaves completely differently though. It's viscous, it gels, holds water,

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and it resists fermentation. So it does make it all of the way through and it does produce far less gas. And that's why it's the fiber that keeps coming up trumps in all of these studies. So there's a 2022 meta-analysis in the American Journal of Clinical Nutrition and it pulled 16 randomized trials with over 1200 people. 66 % responded to fiber versus 41 % to the control. Actually still quite a high amount, 44%.

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Ancillium and pectin were the ones driving that. Doses above 10 grams a day for at least four weeks was sort of the sweet spot they found in that meta-analysis. That has been replicated by a 2026 network meta-analysis that found that viscous fiber types came out best for defecation difficulty with high certainty evidence.

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So the bloating is real as well. So both of these major meta-analyses report significantly more flatulence in fiber arms than the control arms. So if someone says that fiber makes them feel bloated and heavy, I mean, you know how your body acts in response to certain things. that's, you know, that's actually is part of this documented side effect of fiber. So fiber does work for most people. It reliably causes gas in a meaningful number of them.

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the type of fiber matters far more than the amount. So do know that things like inulin and trickery are not what you're looking for and soluble fibers like psyllium definitely is the thing to sort of double down on. Now, something which I found out when I was doing a bit of research for this particular person and subsequently this episode was that there is a condition called dysinergic defecation. And some people call it pelvic floor,

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dysnergia or outlet obstruction. And so what that means is that when you go to have a bowel motion, the pelvic floor muscles and the anal sphincter contract instead of relaxing. So they just fail to relax. So you push, but the exit closes. So it's not a stool consistency problem, not a fiber problem, it's a coordination problem. And this may be a learned behavioral pattern rather than a structural or neurological defect.

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which is exactly why it responds to retraining. So how common is it? Well, in patients with chronic constipation who get referred and investigated, the prevalence of this dyssinergic defecation is up to about 40%. And it may go as high as up to 50%. So it's not a rare condition. And that is potentially half of the people who have failed everything else when it comes to constipation. So how would you know?

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Here are some clues. A feeling of incomplete emptying, like there's more there. Hard, prolonged straining. Feeling blocked at the exit even when the stool is soft. Needing to change position, splint, or use your fingers to help. Spending a long time on the toilet with not much result. So, the great news is, is that if you are nodding along thinking, wow, that's me, you can actually get this fixed. So biofeedback therapy is pelvic floor retraining, and

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It teaches the muscles to relax and coordinate on attempted defecation. And there is some great trial evidence that is pretty strong in this. So there are a bunch of different trials. I'm not going to go through them, but it really does show that you can even do this kind of training at home. The biofeedback training was able to assist and help fix the issue. And I mean, the best advice really is to see a pelvic health physiotherapist.

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There's an excellent person I'm aware of, Dr. Melissa Davidson, I that's her last name. She's the one that trained my osteo-glen-Williams in pelvic floor work, and he's the guy that I see for my pelvic floor injury-related issues. And we talk all the time about these sort of problems that sort of come up with female runners particularly. So you can absolutely self-refer to see most pelvic health physios.

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but definitely go to see one who's been properly trained, I would say. And particularly if you've got the symptom picture I described above and you failed the diet stuff, this could be a really great appointment for you to make. And the mechanical basics that go with this tend to be to put your feet up on a stool so your knees are above your hips, sit for a window of 10 to 20 minutes after breakfast because the gastrocolloid reflex is real and it's strongest

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in the morning after eating. Don't ignore the urge when it comes. If you routinely override it because you're busy or you're not at home, you're training that reflex out. Breathe out and bulge rather than clench and strain. I think that last one is probably going to take a bit of practice if I'm honest. So I really wanted to sort of bring that to your attention just in case you, like a lot of people experience that chronic constipation with no real relief, but

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What do we know about what actually works with constipation? Firstly, kiwi fruit and properly dosed. So the dose is two kiwi fruit a day, not one. And there was a trial that was published in the American Journal of Gastroenterology using 60 healthy controls, 60 with functional constipation, and 61 with IBSC. And they compared two green kiwi fruit against seven and a half grams of psyllium for four weeks and

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Kiwifruit produced a clinically relevant increase of completely spontaneous bowel movements in both of those constipated groups and significantly improved gastrointestinal comfort, which is pretty awesome. Now, Chay and colleagues also compared kiwifruit, green kiwifruit, to prunes in psyllium and all three increased bowel movements and kiwifruit in prunes improved stool consistency.

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straining improved with all three but adverse events were most common with psyllium and least common with the kiwifruit and fewer people were dissatisfied with kiwifruit than the other two. The kiwifruit group also reported significant improvement in their bloating. Doesn't have to be green kiwifruit either, gold has also been found to do the work so gold kiwifruit is great. Now the other thing is is that actually go the fruit with the skin on rather than go for any sort of kiwifruit extract.

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supplements because they don't tend to work as well. I mentioned prunes. Now prunes could be pretty good. 100 grams a day though. God that's not a small amount of prunes is it? And it could bring up other side effects like gas etc. But hey it's food and it's cheap and that could work for you. And of course magnesium oxide. Now many of you would be taking magnesium glycinate already or magnesium citrate or malate because

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Obviously, you know, we know that these are the best absorbed forms of magnesium, but the problem is, is it's not therefore available to do the work that we'd want it to do if you're constipated. With magnesium oxide, its poor absorption actually is a mechanism for why it works. So you might be wondering about the amount. Now, when I'm talking about these other magnesiums like glycinate, biglycinate, et cetera, the amount of elemental magnesium often recommended is a

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if it's around like 300 or say, let's say 250 to 400 milligrams, the amount of oxide, elemental oxide used in trials is actually up to about 1.5 grams or 1500 milligrams. So, you know, it's a pretty significant dose. And one caveat though is if you have impaired kidney function, magnesium oxide is, you know, it's something that you might want to chat to your doctor about because

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It might not be the best thing in this instance if your kidneys aren't working effectively. And the other thing worth noting is that serum magnesium can rise with long-term high dose use, and particularly in older adults. And that, I don't know the clinical significance of that, but your body very tightly regulates its electrolytes. And so if you get this rise, then something is amiss. So do want to be mindful of that. So lastly, I wanna just talk about a couple of things with checking that you might not have

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flagged if you're experiencing constipation. Your fiber's great, your water's great, or whatever, but what have you missed? So the first one could be your supplement stack. If you're taking a lot of supplements, some of them may be causing it. Clearly, iron is a classic offender. Calcium can be too. So it is worth an audit before you add anything else to your supplement.

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The other one is medications. Amitriptyline is commonly prescribed for IBS and for pain and sleep, and it's strongly constipating. Codeine and opioids are some antidepressants, antihistamines, anticholinergics, benzodiazepines, also showed up as a significant risk factor in a large cross-sectional study of over 8600 colonoscopy patients, along with opioids and diabetes, actually.

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So be mindful of any medications and check them if you were someone who has any of those described ones that I've just mentioned, there'll be others. Thyroid. So if this has come on progressively and nothing shifts, getting your thyroid checked is a really good idea, particularly because as our thyroid function diminishes, or if you've got suboptimal thyroid function, then that will slow motility as well. Could also affect your cholesterol.

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Celiac disease is something else, you know, if it's never been formally excluded, it would be worth investigating that. How much food you're actually eating. So I do see this constantly with people that I work with. Low food volume means low stool volume. So if you've been eating in a deficit for a long time or eating very little in the way of actual volume, there's just not that much food to pass. So under eating is a legitimate cause of constipation. So I did want to mention that.

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Sleep and stress, know, poor sleep quality and short sleep duration can come up as these independent risk factors in the epidemiological research. So as does anxiety and depression. So the gut brain access is doing a lot of the work here. And then of course, anything new or alarming, any change in bowel habit that's persistent, any bleeding, any unexplained weight loss, any family history of bowel cancer. So that definitely should be reviewed by your doctor. So

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In closing, if you're constipated and fiber hasn't worked, the answer is probably not more fiber. To work out which problem you actually have, your stool is soft and you still feel blocked and you're straining hard and feeling incompletely emptied, that might be an outlet problem and you'd want to see a pelvic health physio. You don't necessarily want to put on yet another supplement. If you're bloated and gassy on your current fiber, look at what type it is. Inulin and chicory root and greens powders,

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have a different effect than psyllium. If you want to change one food this week, put two green kiwi fruit or gold every day in for four weeks. Don't put just one in and don't just do it sometimes, do it consistently for four weeks, because that's where the trials that show real benefit, that's the dose that they're using. And then if you want to look at magnesium, magnesium oxide is what you're after at quite large doses of about 1.5 elemental.

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grams, which is about, oh no, it's over four times as much as the magnesium glycinate that was otherwise recommended. So I hope that that helps anyone out there who feels a little bit stuck, pun intended, and gives you a little somewhere to go if you feel like you've tried everything, because I totally appreciate that feeling. All right, guys, you have a great week. That's it from me. I'm over on Instagram, threads and X at @mikkiwilliden Facebook @mikkiwillidennutrition.

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head to my website, mikkiwilliden.com, scroll right down to the bottom, pop your name in the little box and jump on my email list. And if you think this is gonna be helpful for anyone else, share the love and pass it over to them so they get to get a little bit more insight potentially into what's going on with them. All right guys, have a good week. See you later.