What triggers IBS? It's not always about food...

If you have IBS, you may have noticed that your symptoms aren't always predictable. One week you can eat something without a problem, and the next it seems to trigger bloating, pain or a change in your bowel habits.

And sometimes it isn't food at all.

A bout of food poisoning, a course of antibiotics, a stressful period at work, poor sleep or hormonal changes can all coincide with the onset or worsening of digestive symptoms. So what is actually going on?

IBS rarely has just one cause.

Different people can develop IBS symptoms for very different reasons.

Sometimes there is an obvious event that precedes the symptoms, perhaps a bout of gastroenteritis,, food poisoning or a period of significant stress.

But I often think of these events as the straw that breaks the camel's back, rather than necessarily being the whole story.

You may already have a combination of factors affecting your gut, and then one additional stressor pushes things beyond the point at which your digestive system can compensate. This is why, rather than looking at IBS in isolation, I like to look upstream and downstream. What has happened in your health history that may have contributed to where you are today? And what is happening now that could be maintaining your symptoms? What can trigger or aggravate your IBS symptoms?

There isn't a universal list, but some common factors include: Gastroenteritis or food poisoning Antibiotic use Certain medications Stress Poor or disrupted sleep Hormonal fluctuations, including changes around the menstrual cycle and midlife Certain foods or eating patterns Alcohol Changes in routine, travel or illness

And often, it's not one factor acting alone.

For example, you might have a period of high stress, sleep badly for several weeks, eat differently and then develop digestive symptoms.

Your gut is constantly responding to what's happening both inside and outside your digestive system.

What do these triggers have in common?

Many of these factors can influence the gut microbiome, gut motility, immune activity and the communication between the gut and nervous system. Antibiotics, for example, can alter the composition of the gut microbiome. Gastroenteritis can disrupt the gut and, in some people, digestive symptoms can persist after the original infection has gone.

Stress can affect gut motility and sensitivity through the gut-brain axis, while poor sleep can influence both stress regulation and digestive function.

And hormonal changes can also affect the way the gut behaves — something that can become particularly noticeable during midlife.

This is why I don't think IBS can always be explained simply by saying: “It's something you ate.” So where does food fit in? Food absolutely matters.

But it's not always the whole story. Rather than automatically removing more and more foods, I want to understand why certain foods might be causing problems in the first place. Is your diet lacking variety? Are you getting enough fibre? Are you eating enough protein and essential nutrients? Are there particular foods that consistently trigger symptoms? Are you digesting your food effectively? And what else is happening in your life at the same time?

This is also why I use Step 1 of my four-step system: CONSIDER.

We look at the whole picture before deciding what needs to change. Sometimes testing can help. Depending on your symptoms and health history, I may recommend further investigation, which can include a comprehensive stool analysis. Stool testing can provide information about aspects of the gut microbiome and can include markers relating to digestion, inflammation and certain microorganisms. It isn't a magic answer, and it doesn't tell us everything about IBS, but in the right person, it can provide another useful piece of the puzzle and help inform the next steps.

It's not always about food

This is one of the most important things I want my clients to understand.

I'm a Nutritional Therapist, but sometimes the answer isn't another change to your diet. If stress, sleep, hormones, movement or another aspect of your health needs attention, I may recommend working alongside another appropriate healthcare professional or therapist. Because if we want to support long-term health and healthy ageing, we need to look at all the pillars — not just what's on your plate.

Your gut doesn't exist in isolation.

It's connected to your brain, immune system, metabolism, hormones and overall wellbeing. And that's why my approach to gut health is about much more than IBS symptoms. It's about understanding the bigger picture, supporting your gut's resilience and helping you build foundations for better health as you age.

Healthy ageing starts in the gut — but it doesn't end there.