Gut Health 101: IBS, IBD & Low FODMAP Foods

Think about the last time your stomach wasn’t on your side. Maybe it was the uncomfortable bloating after a meal, that cramp that hit mid-workday, or feeling sluggish when you needed energy most. When your gut isn’t happy, it doesn’t just stay in your stomach, it affects your mood, your focus, and even how well you train and recover.

Most people will deal with the occasional digestive hiccup. But for some, gut health issues aren’t just now and then; they’re a daily battle. That’s the reality of conditions like Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD). While they’re very different in cause, both can turn eating into a constant guessing game, where a simple meal can mean hours of discomfort.

So, what’s the difference between these two conditions, and why do they cause such similar struggles? Let’s break it down.

It’s easy to mix up IBS (Irritable Bowel Syndrome) and IBD (Inflammatory Bowel Disease). They share some symptoms; like bloating, abdominal pain, and changes in bowel habits such as constipation or diarrhoea but they’re actually very different conditions. Understanding the difference helps explain why nutrition strategies, like the low FODMAP diet, are recommended for one but not always the other.

• IBS is a functional GI tract disorder, which means the gut looks normal under scans or scopes but doesn’t work the way it should.

• It affects around 10–15% of the global population, with women more likely to experience it than men (Zhang & Su, 2025).

• Common symptoms include bloating, cramping, abdominal pain, constipation, diarrhoea, or a mix of both.

• People with IBS often have what’s called a “sensitive gut”, where even small changes (like gas or extra water in the intestines) trigger exaggerated discomfort (Monash University, 2019).

• IBS doesn’t damage the gut physically, but it can have a huge impact on health and wellbeing, work, and social life (Kuźmin et al., 2025).

• IBD is an inflammatory condition that causes visible damage to the GI tract. The two main types are Crohn’s disease and ulcerative colitis.

• Unlike IBS, IBD is linked to immune system dysfunction, chronic inflammation, and sometimes the need for medication or surgery.

• Symptoms can overlap with IBS, bloating, cramping, urgent bowel movements but IBD can also include weight loss, fatigue, and blood in the stool.

• People with IBD may also experience IBS-type symptoms when their disease is in remission (Bertin et al., 2024).
  
  

• IBS = sensitive gut, functional problem (no structural damage).

• IBD = inflammatory disease, physical damage to the GI tract.

Both conditions can make food feel like the enemy, but the low FODMAP diet has been shown to be especially effective for IBS, helping to reduce bloating, abdominal pain, and improve day-to-day comfort. And that brings us to the next piece of the puzzle: what exactly are FODMAPs, and why do they cause so much trouble?

Here’s where the science gets interesting. Researchers at Monash University discovered that many people with IBS react strongly to a group of carbohydrates known as FODMAPs.

FODMAPs are short-chain sugars that the small intestine doesn’t fully absorb. Instead, they travel slowly through the GI tract, drawing in water as they go. When they reach the large intestine, gut bacteria ferment them quickly, producing gas. For people with a sensitive gut, this combination of extra water and gas stretches the intestinal wall and triggers abdominal pain, bloating, cramping, and bowel changes (Monash University, 2019; Bertin et al., 2024).

The term FODMAP is actually an acronym:

• Fermentable – gut bacteria ferment these carbs, producing gas.

• Oligosaccharides – fructans & galacto-oligosaccharides (wheat, rye, onions, garlic, legumes).

• Disaccharides – lactose (milk, soft cheeses, yoghurt).

• Monosaccharides – excess fructose (honey, apples, high-fructose corn syrup).

• And

• Polyols – sugar alcohols like sorbitol and mannitol (in some fruits, veggies, and sweeteners).
  
  

The tricky part? High FODMAP foods are found in many everyday meals, from apples and bread to onions, milk, and even some protein powders or snack bars. That’s why symptoms can feel unpredictable.

For most people, FODMAPs aren’t a problem. But for those with IBS, research shows they can be a major trigger. The good news is that by identifying and reducing high FODMAP foods and swapping them for low FODMAP foods, many people experience real relief. In fact, studies show that about 3 in 4 people with IBS feel better within 2–6 weeks of starting a low FODMAP diet(Monash University, 2019; Bertin et al., 2024; Kuźmin et al., 2025).

So, how does this diet actually help settle symptoms and what kind of improvements can you expect? Let’s take a closer look.

The low FODMAP diet isn’t about cutting out all these foods forever, it’s a structured, short-term plan designed to calm a sensitive gut. It works in three phases: restriction, reintroduction, and personalisation, usually guided by a dietitian. The goal isn’t to avoid foods for life, but to identify which ones are your personal triggers and then bring back variety where possible (Bertin et al., 2024).

By limiting high FODMAP foods, you reduce the amount of gas and water pulling into your GI tract. For people with IBS, this means less stretching of the intestinal wall and fewer flare-ups of bloating, constipation, diarrhoea, and abdominal pain (Monash University, 2019).

Research shows the results are significant:

• 3 out of 4 people with IBS notice symptom relief within just 2–6 weeks (Monash University, 2019; Bertin et al., 2024).

• Randomised controlled trials have found the diet improves abdominal pain, bloating, stool consistency, and urgency compared to standard dietary advice (Zhang & Su, 2025).

• One review reported that 52% of people achieved a meaningful improvement in quality of life on a low FODMAP diet, compared to just 21% on a regular diet (Kuźmin et al., 2025).

Some studies even suggest improvements in sleep, fatigue, and overall health and well-being (Kuźmin et al., 2025).

It’s important to remember: the low FODMAP diet isn’t a cure for Irritable Bowel Syndrome, and it doesn’t work for everyone. Around 1 in 4 people won’t see major changes (Monash University, 2019). It’s also restrictive, which means doing it long-term without professional support can affect nutrient intake and even reduce beneficial bacteria in the gut microbiome, like Bifidobacteria (Bertin et al., 2024; Zhang & Su, 2025).

That’s why the personalisation phase matters; it helps restore variety and balance while still keeping your symptoms in check.

So, what does a low FODMAP diet actually look like day-to-day? It often comes down to smart swaps: choosing low FODMAP foods that are easier on digestion while still giving your body the fuel it needs.

So how do you put the low FODMAP diet into practice? It often comes down to swapping one food for another. By replacing common high FODMAP foods with low FODMAP alternatives, many people find they can enjoy a wide variety of meals without the discomfort.

Here’s a quick guide based on Monash University’s testing:

These swaps don’t just take the pressure off your GI tract; they also lay the foundation for figuring out which foods your body tolerates best during the reintroduction and personalisation phases.

And it’s not just about food. You know those supplements you rely on every day; your protein powder, greens powder, or collagen supplements? Don’t worry, you don’t have to give them up. The good news is there are low FODMAP and even Monash-certified options available in ASN’s Gut Health collection, so you can keep supporting your health and wellbeing without upsetting your gut.

Food swaps are one part of managing gut health but what about your supplements? The good news is you don’t need to compromise here either. Many everyday staples have low FODMAP options, and one of the most trusted brands leading the way is Raw by Amazonia.

Built on clean, plant based protein powder and certified organic nutrition, Raw by Amazonia is designed to be gentle on digestion while supporting long-term health and wellbeing. Their range uses certified organic ingredients, making it a natural fit for anyone managing IBS or following a low FODMAP diet.

• Raw Protein – a smooth, vegan protein powder that’s dairy free, lactose free, and Certified FODMAP Friendly — perfect for everyday recovery.
  
  

•  Organic Fibre – a Certified Low FODMAP formula that supports digestion and helps ease constipation naturally.

With Amazonia, you don’t need to compromise on the supplements you rely on every day. It’s about supporting your gut health and your goals, side by side.

Your gut plays a big role in your overall health and wellbeing. For those with IBS, understanding FODMAPs and making simple swaps from low FODMAP foods to choosing the right vegan protein powder or greens powder, may ease bloating and discomfort, helping you feel more in control. Research shows up to 3 in 4 people notice improvements within weeks on a low FODMAP diet.

At ASN, our curated collections in Gut Health, Protein Powder, Greens, and Health and Wellbeing make it simple to find what works for you. Shop online, in-store, or via Click & Collect and keep your gut and your goals supported without compromise.

Bertin, L., Zanconato, M., Crepaldi, M., Marasco, G., Cremon, C., Barbara, G., Barberio, B., Zingone, F., & Vincenzo Savarino, E. (2024). The Role of the FODMAP Diet in IBS. Nutrients, 16(3), 370–370. https://doi.org/10.3390/nu16030370

Kuźmin, L., Kubiak, K., & Lange, E. (2025). Efficacy of a Low-FODMAP Diet on the Severity of Gastrointestinal Symptoms and Quality of Life in the Treatment of Gastrointestinal Disorders—A Systematic Review of Randomized Controlled Trials. Nutrients, 17(12), 2045–2045. https://doi.org/10.3390/nu17122045

Monash University. (2019). About FODMAPs and IBS | Monash FODMAP   - Monash Fodmap. Monashfodmap.com. https://www.monashfodmap.com/about-fodmap-and-ibs/

Zhang, H., & Su, Q. (2025). Low-FODMAP Diet for Irritable Bowel Syndrome: Insights from Microbiome. Nutrients, 17(3), 544–544. https://doi.org/10.3390/nu17030544