Welcome to episode 47 of the Inside Knowledge podcast. I’m Anna Mapson. It’s really common when I work with people to have conversations about how all their digestive troubles started. After all, if we know what caused IBS, then we can avoid it in future or try to remedy it. The problem is, is that there’s often a very complicated interweave between our lifestyle, our diet. And then physical changes in the gut, that could be down to different bacteria, down to your genetics.
But I’m going to go through some of these in this episode and see if any of these resonate with you.
The causes of IBS can be hard to find
Whilst we might not always find the original root cause, what you can do is try and think about what sort of presentation that your digestive issues are. And so then you can try and think about how to address them.
Syndromes are hard to treat
The term irritable bowel syndrome is a collection of symptoms.
Syndrome is normally just something where we don’t really know what causes it or how to treat it. It’s just a collection of symptoms that seem to go together. And that is the problem with IBS. Because it’s so different in each person, there is no one treatment approach that can definitely work for everybody. Therefore people feel a little bit lost.
So if you’ve been desperately searching for the cause of your IBS and you’re feeling very confused, hopefully I will try to make it clear what I’ve understood from working with hundreds of people who’ve got IBS.
IBS is a biopsychosocial disorder
Firstly, IBS is sometimes referred to as a biopsychosocial disorder. That means bio, there’s biological causes.
This could be down to your genetics, could be down to physical structure of your body, or the motility of your gut. The sensation of pain. Could be the amount of bacteria in the small or large intestine. These are physical or chemical changes, things that are affecting you physically. So that’s the biology.
The psychological element really relates to our thoughts, our emotions, and our behaviours. So how we’re coping with the symptoms, how stressed you are, what anxiety levels are like, so all to do with your mental health.
And then the social side is like your socio economic status. How wealthy you are. Where you live. Cultural factors like your work schedules, whether you live alone or with family. And whether that is beneficial or not for you. These things really have a great impact on our digestion.
Past infections can be a cause of IBS
I’m going to go through five different areas and starting off with post infectious IBS. Did your IBS start after an episode of food poisoning? Maybe a dodgy kebab or seafood meal that really gave you stomach bug and you were vomiting, diarrhoea. You were never the same again. After any bout of gastroenteritis or a stomach infection like that, you are six times more likely to have IBS. This risk carries on for two to three years after the event.
So it doesn’t have to be that immediately after contracting that bug you carried on having symptoms. It could be that two years ago you had an infection and then your IBS kicked off a bit later in life. Post infectious IBS is one of the most common causes of IBS and it’s thought to cause around five to thirty percent of IBS cases. So pretty common.
How stomach bugs can cause IBS
Listen to episode 10 where I go into much more detail about post infectious IBS. But the way that this works is that you eat something that’s got a dodgy bug in it. Something like Campylobacter, Shigella, Salmonella, E. coli. These organisms come into our body through dirty water or food that’s gone off.
And the way it affects us is it disrupts the intestinal barrier between the gut and the inside tissues. It also can affect your motility and it triggers chronic inflammation.
These are the causes of the IBS. So when we have an infection like that, an acute infection, our body draws water into the bowel. That creates the diarrhoea and vomiting to try and wash the bug away.
Antibodies affecting your gut motility – CDT-B
We also produce an antibody called cytolethal distending toxin or CDT B. This antibody can also affect our motility by becoming an antibody to a protein that we actually need for the motility process.
Sometimes, once you’ve had this effect of the motility slowing down in the small intestine, you’re less able for the the cleaning process of the migrating motor complex . That’s your internal washing, like housekeeper, that cleans out your small intestine. If that is reduced, you’re more likely to have an overgrowth of bacteria.
Or to slow down the cleaning process which can lead to bits of old food, bacteria, like cell renewal just slowing down. So we do want that migrating motor complex to work effectively and when it’s slowed down by this antibody that can lead to IBS type symptoms.
You can test for the antibody
There is actually a test that you can get now, it’s a blood test and it’s only available in one or two places in the UK that can test you for this antibody.
So it is possible to check whether that is the cause of your IBS. Or not.
Gut motility issues can cause IBS
So the second cause of IBS that I commonly see is motility issues. Motility is the speed with which food travels through your intestine. It’s not necessarily related to that migrating motor complex which isn’t necessarily about the passage of food. It’s about how your small intestine is cleaning itself.
This next issue about causing IBS is whether food is travelling too fast or too slow. Slow movement of food through the digestive tract can cause an overgrowth of bacteria, which can then increase constipation.
Slow transit time in IBS-C
So, sometimes you get into a vicious cycle with slow movement of food that’s allowing more of an overgrowth of bacteria. These microbes produce methane gas, which then slows the gut transit down even more.
Causes of sluggish digestion, which is common in constipation predominant IBS. Can be caused by things like not eating enough food, not eating enough fibre. If you’re having a very low fibre diet, you may not be triggering a bowel movement. Because you’re not getting enough content coming through to the large intestine.
Physical obstructions slowing down the gut
Maybe there are some structural issues like adhesions where your small intestine is kind of sticking to other organs. There’s extra loops and twists for it to go through and that can slow things down. Maybe there’s some problems with the nerves or the smooth muscle that is actually weakening the digestion.
This can be common in people who have hypermobility conditions or low functioning thyroid. Where the smooth muscles are just not working as effectively as they could. Or sometimes slowing down your digestion before your period can happen in women.
Slow transit time causes constipation
Any of those causes a slow digestion. Then that you’re getting more water being reabsorbed from the stool in the large intestine which then leaves hard, dry stools. So you get like the type 1 little pellety poos. Or big large poos that are just stuck there and you’re feeling very bloated. And then this causes more gas, partly because the gas can’t get out. It’s blocked by a large poo in your large intestine.
Or that it’s just fermenting more by the large intestine bacteria. So there’s more fermentation in the gut.
Fast motility
Now, the exact opposite of that is the fast motility, food passing way too quickly through your gut. This can be caused by high anxiety or like chronic stress. Your body is just evacuating food in order to deal with that fight, flight or freeze situation. Maybe there’s food intolerance there where some particular carbohydrates aren’t well digested. That can draw water into the bowel to create diarrhoea.
There may be gastric dumping where food is coming out of your stomach too quickly into the small intestine. So it’s literally just being dumped out of the stomach before it’s ready. And that can cause feelings of bloating, fullness, pain, gas.
Maybe you’re having too much caffeine or alcohol. These are gut stimulants and really can speed up the gut transit time.
And then before your period. So if you’re having periods, sometimes as your period starts or During it, you can get diarrhoea as well.
SIBO can be a cause of IBS symptoms
The third cause of IBS could be small intestine bacterial overgrowth or SIBO. Although SIBO is a specific condition and it’s separate from IBS, it might be the cause of symptoms that you’ve always thought of as IBS.
It’s thought to affect up to 78 percent of people who’ve got IBS may have an overgrowth in the small intestine. If you don’t know anything about SIBO then do listen to my previous episodes which is episode 11, episode 12 and episode 31. Those three talk about what is SIBO, how to treat it and then specific supplements that are good for SIBO.
The reason I pulled this out as a specific cause of IBS is that it can be treated. You can take antibiotics, you can take substances that kill off the microbes. That can improve symptoms that you’ve always thought were IBS. So, think about SIBO, whether it could be a cause of symptoms.
SIBO is often also one of the causes of other types of maldigestion of food. If you’re not digesting your food particularly well, or if you’ve got a problem with bile acid diarrhoea, which is where you are not reabsorbing a lot of your bile salts, and they are causing diarrhoea. These two things can be triggered by SIBO.
So knowing whether you’ve got SIBO in the first place is really important.
SIBO causes poor digestion of food
Now, what I mean by improper digestion of food is that some foods are not broken down properly in your small intestine because you haven’t got the right digestive enzymes, or maybe that you’re eating like a really high amount of fibre. Or eating a lot of foods that are high in artificial sweeteners.
For example, these are all part of the FODMAP diet and some of these foods can be causing IBS symptoms. So, if you’re not digesting them, it’s mostly down to not having the right enzymes coming in. At the beginning of the digestion process. Or not having enough stomach acid, for example. That is going to kickstart your digestion process.
Food intolerance can cause IBS
Some people will have a food intolerance, which means that you don’t have the right enzymes in order to break down certain sugars or carbohydrates in your food. Lactose intolerance is a key example of this where people don’t have the enzyme lactase in order to break down the sugar that’s in milk. You can also have an impairment of certain digestive enzymes for other types of carbohydrates as well. So other foods could be triggering your symptoms.
Try the low FODMAP diet
Now a good way to tackle this or to know whether this is a problem for you is to go on a low FODMAP diet. Take all of these fermentable fibres out of your diet and then bring them back in slowly one by one.
What you might find is that certain foods are osmotic and that means that they’re bringing water into the small bowel and these are particularly the polyols sorbitol, mannitol.
Polyols can cause diarrhoea and bloating
But also other sweeteners like xylitol which are often in processed foods as a non sugar sweetener. So these foods are commonly found in things like celery, sweet potato, mushrooms, peaches, sweet corn, blackberries, cabbage. These are all high in these polyols.
As you reintroduce these foods, you would be able to test whether that is one of the causes of your diarrhoea if you’ve had a significant improvement on the low FODMAP restriction phase.
Fructose can trigger IBS-D
The other FODMAP group that can have this effect is high fructose foods, typically found in grapes, mango. Little cherry tomatoes, red pepper, broad beans, and asparagus. So these foods as well, you might find that if you were eating a really high fibre diet with lots of fruits and vegetables, maybe these were the cause of your diarrhoea.
So sometimes they can be a problem with digesting the foods and your ability to break them down because obviously that doesn’t apply to everybody but just for some people with IBS, those sorts of foods would be an issue.
The other sorts of foods that might have been a real trigger, which you will get through the doing the low FODMAP diet restriction process, is whether you’re eating a lot of insoluble fibre that could be irritating the gut and causing diarrhoea in that way. or causing very sluggish constipation.
The gut brain connection – a cause of IBS
And then lastly, I want to come on to the gut brain connection. This is the fifth area, the most common cause of problems with IBS. The way we think and feel can have a massive impact on our digestion. The gut brain connection, our mood, it all affects our ability to break down what we eat, but also how fast things are moving through us.
So in high stress situations when our body is primed for fight or flight, we’re not going to prioritize digesting a meal and extracting calcium out of the food we’ve just eaten. No, our body is ready for danger and this can lead to less blood flow to the gut, resulting in either constipation, could be bloating, fermentation, diarrhoea, and gas.
The brain and mood affects gut motility
So, all those common symptoms of IBS. The ways in which it affects your digestion is either It speeds up motility or slows down motility. Or it increases the amount of hypersensitivity. That is how much sensation you feel in your digestion to your brain. The brain gut connection is overactive and hypersensitive, meaning you feel more pain.
You feel more sensations of things moving through you compared to people who do not have IBS. High sensitivity can be primed right from the time you were born. Before you even will remember. Sometimes, our childhood, the way we’ve grown up, the family situations we were in as a young person have a big impact on the way that our body responds to stress. And how we are primed to feel more stress than other people, for example.
So really strong adverse childhood events, so traumas, abuse, accidents, domestic violence. These kind of traumas unfortunately, lead people to be twice as likely to have IBS as people who didn’t have adverse childhood experiences.
Family experiences around food shape our digestion
You may also have learned to think about food and think about your digestion in a certain way from those around you as you were growing up. We also have chronic stressors, so things like busy work, relationship issues, parenting problems. These might not be one key crisis that you might consider a big stress, but it’s just the ongoing chronic stress that can lead to increased IBS symptoms.
So going through all of those possible causes or triggers for IBS. I wonder what’s come up for you.
How to start tracking your symptoms
If you would like to start working out what’s happening right now that could be triggering your symptoms, you might find it interesting to listen to my episode on tracking for IBS where I’ve gone into lots of the data that I collect with my clients at the beginning of the gut reset.
I ask them to complete a diet diary, fill in what they’re eating. But also how their symptoms are over a couple of days and then look at that. Tracking your symptoms is a really good way to see if you can spot any patterns on your own.
Using a diet diary for IBS
It’s a good way to just try and get back in touch with what you’re actually doing because you can think to yourself, yeah, I’ve got a healthy diet, or yeah, I know I’m getting lots of exercise. But actually when you objectively see it written down and you look at it thinking about how your symptoms were over the course of a week. Whilst you’re also noting down How your sleep was, how much movement you got in, what your stress levels were like, what did you actually eat for five days.
These things are really helpful. Obviously, there are lots of other causes or things that could be upsetting your digestion that I haven’t mentioned today.
Other causes of IBS
For example, we haven’t really talked about bile acid malabsorption, about bacterial infections, about medication that can affect your IBS. So there are lots of other things and other reasons, but these tend to be some of the biggest groups of issues that I see with people who come to work with me.
It doesn’t always necessarily mean I know exactly what to do straight away, but that is the joy of what I get from working with people over three months is that we can figure things out. I think about what your collection of symptoms might mean. And how we can translate or interpret those into an action plan.
What food you should be taking. What supplements you should be taking and should not be taking. And how you can adjust how you’re eating and how you’re living to better suit your symptoms. So that is the sort of groupings of things that I look at. Is it about your motility? Is it mostly on your diet? And sometimes it is a combination of all of these things.
Causes of IBS can be linked
As you might have noticed, some of these causes are triggered by another cause. For example, SIBO, which could be triggered by that post infectious IBS. Then gives you SIBO, then gives you fructose malabsorption, for example. Those things are all related in a ladder. Just knowing that it was caused by a food poisoning incident doesn’t necessarily mean that we know exactly what will happen down the cascade. But it just helps to better understand it.
So, if you’re interested in that, go and listen to episode 6, where I go through all the tracking information and you can also download the template for free. The template that I share with my clients when I work with them in the gut reset.
Right, there we go, I will leave it there for this week, but thank you very much for listening to this episode of the Inside Knowledge. Better digestion for everyone.