6 CAUSES OF DIARRHOEA (and what to do about them)

Diarrhoea. Not something that we like to talk about, but something that can really affect our lives in a not so great way.

Find yourself running to the bathroom after eating out with friends? Sick of having to excuse yourself from meetings to dash to the ladies? Annoyed at your friends teasing your because you know where every toilet in your town is? This one’s for you.

Let’s face it - diarrhoea sucks. It gets in the way of you living your life and enjoying yourself! Well, the good news is that it doesn’t have to. If you suffer from diarrhoea, it’s likely you have too much fluid in your colon, which speeds up transit time and makes poo watery. However, there are different causes of this. By working out what’s causing yours, you can do something about it. You can learn what’s triggering it and then choose to avoid those things…That puts you in the driving seat and means you know what you need to do to avoid those bathroom dashes.




Normally, diarrhoea is only temporary. When you’re ill or get food poisoning, your body is trying to get the parasite or bug out of it as quickly as possible…resulting in diarrhoea. This also applies to certain medications, which can lead to the same effect.

WHAT TO DO ABOUT IT - In these cases, it’s best just to let it run its course and make sure that you re-hydrate with water and electrolytes. Coconut water is a great, natural source of both of these.


If you’ve got any sort of inflammation in your small intestine, it makes it much harder for your gut to absorb water from your poo. This leaves them watery and loose.

WHAT TO DO ABOUT IT - If you think this could be the case, it’s best to go and see a doctor about it. They’ll be able to run some tests to check for any inflammation.



FODMAPs are all sugars that aren’t properly absorbed in the gut, which therefore triggers symptoms, including diarrhoea. This is because, sometimes, different people can lack the enzymes needed to break down some of these sugars. A good example of this is lactose. People who are intolerant to milk lack the digestive enzyme lactase, which is needed to break down the lactose in milk. Out of the different groups of FODMAPs, fructose, polyols (see next point) and lactose are most likely to cause looser bowel movements. This is because they attract water into the small intestine, speeding up digestion.

WHAT TO DO ABOUT IT - Look into the low FODMAP diet and see whether you think any of these things could be triggering you.



As well as sugars, ‘sugar free’ or ‘diet’ products can also cause diarrhoea. Sweeteners ending in ‘ol (e.g. sorbitol, mannitol and xylitol) are part of a group of FODMAPs called polyols, and are found in diet products, e.g. sugar free gum. These trigger diarrhoea by attracting more water into the small intestine.

WHAT TO DO ABOUT IT - Try cutting out this group of sugars for a few weeks and see if you feel any better. Be careful though, as these can be sneaky ingredients in lots of products, so you’ll have to do some careful label reading.



Stress causes your intestines to contract, which means it moves your stool through it more quickly. This means there isn’t enough time for much water to be absorbed out of your stool by your colon, so it comes out watery and loose.

 WHAT TO DO ABOUT IT - Work on reducing your stress levels. The first step to reducing stress is to take some time to reflect on what’s causing you stress. If it’s something that can be changed, e.g. you’ve taken on too many projects at work, then take action to do something about it, e.g. speak to your manager about delegating. However, there are lots of stressors that we can’t control, e.g. a delayed train, so try and find little ways throughout the day to manage stress. This could be a 10 minute morning meditation, an evening walk, or simply breaking from work to eat your lunch.


6. IBS

Finally, diarrhoea can be a symptom of Irritable Bowel Syndrome (IBS). Irritable bowel syndrome refers to a group of symptoms coming from the bowel that affects 15% of the world’s population. There’s no disease (which is great), just a change in how the gut moves (this is called gut motility). This change in gut motility causes symptoms and changes in your poo! If motility increases, it means food moves through your system more quickly, so you’ll suffer with diarrhoea.

IBS is normally classed into sub-groups, depending on your symptoms. You’ll be classed as having IBS-D if your main symptom is diarrhoea, and about 1/3 of IBS sufferers have this type, so it is not uncommon.

WHAT TO DO ABOUT IT - The great thing is, if your diarrhoea is a symptom of IBS, there are lots of things you can do to relieve it, which I’m going to write a post about next week. However, in the meantime, it’s important to get officially diagnosed with IBS by a doctor, just to make sure you don’t actually have a more serious condition. So, if you think you could have it, use this week to go and see a doctor. Then, if you do get a diagnosis, you’ll be all ready for next week’s post.


Diarrhoea is a totally unsexy topic, but something that can really get in the way of us living our lives. BUT, it doesn’t have to. By understanding the cause of your diarrhoea, you can discover what you need to do to relieve it.

6 Causes of Diarrhoea + What to Do About Them

1. Short term illness and medications - let it run it’s course and keep hydrated

2. Inflammation in small intestine - go and see a doctor

3. Eating Sugars..a.k.a. FODMAPs - look into the low FODMAP diet

4. Eating Sugar Free Products - cut out this group for a few weeks and see if you feel any better

5. Stress - add in daily stress management practices, like meditation or a walk

6. IBS - get diagnosed by a doctor and then sign up below to get sent next week’s article on How to Relieve IBS-D

One or more of these things could be causing your diarrhoea. If you’re not sure which one it is, start by looking into one of them this week. Once you’ve decided whether that one does or doesn’t apply to you, move onto the next.

One of the most common causes on this list is IBS. If you think your diarrhoea is down to IBS, there are lots of things you can do to help relieve it. Pop in your email address below, and I’ll send you next week’s post, with practical tips for relieving diarrhoea, straight to your inbox.

Which of these do you think is causing your diarrhoea? Let me know in the comments below.

Thank you so much for taking the time to read this and letting me be a part of your journey in taking control of your gut, eating well and living your life.

Sophie x


Sophie BibbsComment