Ask the experts: What’s the relationship between stress and IBS?

April is a particularly good time to be asking this question. It’s both IBS Awareness Month and Stress Awareness Month, so I suspect lots of people will be paying even closer attention than usual to their symptoms. Sadly, for many those symptoms will include both gut and mental health concerns – and that’s because we know IBS and stress are closely linked.  

The gut microbiome is the collective name to the trillions of bacteria, viruses and fungi that live in our guts - mostly the colon or large bowel. In the last few decades, we have learnt a huge amount about the impact the microbiome has on the health not just of your gut but also other parts of your body. 

Gut brain connection 

Your brain and gut are very closely linked. Your gut is packed with nerve cells which control many aspects of digestion, including release of fluids which help you digest food and blood supply to absorb nutrients into your bloodstream. There are over 100 million of these nerve cells, which are known as the enteric nervous system. At one end, they are connected to your brain - but at the gut end, they are in close constant contact with your gut microbiome. 

The gut-brain axis – the connection between the gut and the brain – is a two-way street. What’s going on in your brain is fundamentally affected by the health of your gut microbiome. And in recent years a wealth of evidence has emerged to prove the impact of the microbiome on mental as well as gut health.  

How does your gut affect your mood? 

Animal studies 20 years ago showed that raising mice in sterile conditions, so they basically had no functioning gut microbiome, resulted in higher levels of stress hormones. By contrast, transplanting gut bacteria from either severely depressed or normal-mood humans into the guts of these microbiome-free mice resulted in them behaving in ways that suggested depression or normal mood. 

Irritable bowel and stress – what’s going on? 

Irritable bowel syndrome, or IBS, is what’s known as a ‘functional bowel disorder’. That means there’s no abnormality with any one bit of the bowel if you examine it under a microscope, but the various parts of the gut don’t work smoothly together. The result is a combination of: 

• Pain (often colicky and relieved by opening your bowels). 
• Bloating, which tends to get worse over the course of the day or after eating. 
• Increased wind. 
• A change in your bowel habit, which could include diarrhoea, constipation or a mixture of the two. 
• Needing to rush to the loo to open your bowels. 
• Feeling sick. 
• Other non-gut symptoms including tiredness, headache or bladder symptoms. 
  

Irritable bowel and stress - chicken and egg?

There’s little doubt that living with IBS is stressful in itself. The condition can have a huge impact on your ability to function day-to-day, as well as your social life. So it’s hardly surprising that if you have IBS, you’re more likely to have anxiety and/or depression. But in recent years, the gut-brain connection and the importance of the gut microbiome in both physical and mental health have led scientists to investigate an alternative connection. It’s now thought that inflammation and irritation in the gut, caused by dysbiosis (an imbalance of the gut microbiome) could be triggering mood changes in the brain. 

There’s no doubt that being under a lot of stress increases your chances of developing IBS, or of flare-ups of your existing IBS. Scientists now describe IBS as ‘a combination of irritable bowel and irritable brain’. Stress can influence many aspects of your gut function, including sensitivity to pain, the movement of food along your digestive tract and the digestive process.  

This happens because of a complex interplay between hormones, the immune system and the nervous system. Stress leads to release of ‘fight or flight’ hormones which trigger a range of physical reactions. It can also alter the interactions in the gut-brain axis, by causing the body’s immune system to release chemicals that lead to inflammation. Stress also changes your focus, so you may find it harder to take your mind off your pain. It downgrades pathways that can let your brain override pain signals. And finally, it can affect the physical functioning of your gut, altering the way food is moved through your digestive system. 

How can I help myself? 

The first thing to do is to recognise that neither stress not IBS is your fault. The second is to realise that just because stress has an impact on your IBS symptoms, that doesn’t stop IBS from being a very real condition. For too long, we have underestimated the very real physical impact of psychological conditions. Now, by recognising that your enteric nervous system is like a second brain in your gut, we can really start to focus on tackling all the triggers for IBS. 

Management of stress-related IBS can be largely divided into: 

Stress management 

• Be kind to yourself. Find time for loved ones, hobbies and activities you enjoy. This is particularly true if you find them really absorbing, so you’re wholly focused on the moment. 
• Relaxation techniques such as breathing exercises, progressive muscle relaxation or yoga can help calm the constant flow of thoughts that trigger changes that worsen IBS. 
• Mindfulness is about being focused on the here and now without judging yourself. Being truly aware of your surroundings – sounds, sights, smells, sensations – helps you get back in touch with your physical environment. This can help calm your nervous system down and reduce your body’s stress response. 
• Aim for 7-9 hours of sleep a night. It may be easier said than done, but ensuring your bedroom is a haven of calm; avoiding stimulating activities (including scary movies and scrolling your phone) before bed; and writing down and ‘parking’ your worries if they come to you in bed can really help. 

Keep your gut happy 

• Get enough fibre in your diet (in the UK we get about 20 grams a day, when the recommended is at least 30 grams). Fibre provides food for the good bacteria in your gut microbiome and can help them crowd out the unhealthy bacteria that lead to dysbiosis – an imbalance in your gut bacteria. If insoluble fibre makes your symptoms worse, focus on soluble fibre instead. 
  

Consider talking therapy 

• Cognitive behavioural therapy (CBT)aims to help you recognise and challenge unhelpful negative thought patterns that can cause or perpetuate stress. 
• Psychotherapy can help you understand and cope with the deep-seated emotional issues that may be tiggering your symptoms. 

The bottom line 

Stress and IBS are closely linked – and stress can have a profound impact on the physical functioning of your body. Your gut microbiome plays a pivotal role in the gut-brain axis, which can affect both physical and mental health symptoms. Coping mechanisms to deal with stress can help relieve symptoms of IBS. And a healthier gut microbiome may improve both your physical and mental wellbeing. 

More Ask the Experts

What can I do to look after my gut microbiome

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