Fibermaxxing with IBS? How to increase fibre without bloating
On TikTok and Instagram, lots of people are currently counting their fibre the way they used to count protein. The trend is called fibermaxxing. If you have IBS and join in, you often notice after two or three days that your stomach feels tight and starts to rumble. That is rarely down to the fibre itself. It comes down to the amount, the pace and the choice of foods. Here's how to do it better with a sensitive gut.
What's behind the fibermaxxing trend
The idea is simple. Pack as much fibre as possible into every meal, often with chia seeds, pulses, wholegrains and powders from a tub. The core idea is actually right. Most adults eat less fibre than recommended. The German Nutrition Society and the Swiss Society for Nutrition give a guideline of at least 30 grams a day.
The problem is how people get there. In many videos the amount is doubled overnight. On top of that, the foods that end up on the plate are often the very ones that are rich in FODMAPs. Lentils, large portions of chickpeas, wheat bran, inulin or chicory fibre in bars. For a healthy gut that is already quite a change. For an irritable bowel it is too much.
Why fibermaxxing causes bloating with IBS
Many types of fibre are fermented by bacteria in the large intestine. This produces gas. A healthy gut gets used to it over time. With IBS, the bowel wall often reacts more sensitively to stretching. The same amount of gas then feels like a balloon.
On top of that, some types of fibre are FODMAPs themselves. Fructans and galacto-oligosaccharides, GOS for short, are found in wheat, rye, onions and pulses. Ramping up these sources all at once triggers exactly the symptoms that the FODMAP diet had brought under control. Small amounts add up, too. There's more on this in our article on FODMAP stacking.
Blood in the stool, unintended weight loss, fever or new symptoms from around the age of 50 are not part of the typical picture of IBS and cannot be tackled with diet alone.
Soluble and insoluble fibre compared
Not all fibre behaves the same way. The British NICE guideline on IBS recommends cutting back on insoluble fibre such as bran and, where needed, favouring soluble fibre such as psyllium husk. In practice this matches what many people with IBS experience.
| Type | Examples | With IBS |
|---|---|---|
| Soluble, low fermentation | Psyllium husk, oats | Usually well tolerated, binds water |
| Soluble, highly fermentable | Inulin, fructans, GOS | Often causes bloating |
| Insoluble | Wheat bran, skins | Can make pain worse |
| Resistant starch | Cooled potatoes, rice | Increase slowly, varies from person to person |
Resistant starch and psyllium husk in the new study
Resistant starch is considered good food for gut bacteria. It forms, for example, when cooked potatoes, rice or pasta cool down. With IBS it has so far been unclear whether it does more good or causes more bloating.
A small pilot study at Edith Cowan University in Australia took up exactly this question. It looked at how people with IBS react to resistant starch when it is taken together with psyllium husk. The combination appeared to be better tolerated than resistant starch on its own. However, it is a pilot study with only a few participants. Larger studies still need to confirm the result.
The direction fits earlier findings. In 2022, researchers at the University of Nottingham showed that psyllium husk markedly reduces the gas produced by inulin in the large intestine of people with IBS. Psyllium husk forms a gel that apparently slows down fermentation. For everyday life, this means psyllium husk can be a good partner when you slowly increase other types of fibre.
With IBS, more fibre is not a sprint. If you increase it slowly, you usually get further than if you change everything in three days.
Low FODMAP fibre sources for every day
Monash University has tested many high-fibre foods that are low FODMAP in normal portions. You'll find the exact serving sizes in the Monash app or in our FODMAP list.
Grains
Oats, quinoa, brown rice, buckwheat. A good base for breakfast and lunch.
Seeds
Chia seeds, linseed, psyllium husk. Start with small amounts and always drink enough.
Fruit and vegetables
Kiwi, orange, firm banana, carrots, potatoes with their skin, courgette, aubergine.
On the go, try the Fody High Fiber bar. It is low FODMAP and contains no chicory inulin, which is found in many other fibre bars. And if you prefer your vegetables as soup, you can add a portion with Bay's Kitchen Carrot & Coriander Soup without having to think about onions or garlic.
Fody Chocolate Chip Cookie High Fiber bars, 3 pieces (3 × 40 g)
Bay's Kitchen Carrot & Coriander Soup (300 g)Fibermaxxing with a plan: step by step over four weeks
The plan below is a suggestion based on experience. It assumes that you already know your main triggers, for example after the elimination and reintroduction phases of the FODMAP diet. Make a short note every day of what you ate and how your stomach feels.
- Week 1. Just one change. Swap your breakfast for a small portion of oats or porridge with a kiwi. Drink enough water throughout the day.
- Week 2. Add resistant starch. For example, potatoes cooked and chilled the day before as a salad, or cold rice in a bowl. Start with a small side portion.
- Week 3. Now add psyllium husk. Start with half a teaspoon a day, stirred well into a large glass of water. If that goes well, increase to one teaspoon after a few days. A tablespoon of ground linseed in yoghurt also fits into this week.
- Week 4. Build up your second main meal. Quinoa or brown rice instead of white rice, vegetables with their skin, a fibre bar as a snack.
If it gets uncomfortable, simply go back one step and stay there for an extra week. Nobody expects you to reach 30 grams after four weeks. A few extra grams that you tolerate well are worth more than a number on paper.
Psyllium husk can delay the absorption of medication, so it's best to take it at a different time from tablets. It also dampens the rise in blood sugar after meals, which matters for diabetes medication, and it is not suitable if you have a narrowing of the bowel.
Frequently asked questions
Is fibermaxxing dangerous with IBS?
It is usually not dangerous, but it is often uncomfortable. If you increase fibre too quickly and with high FODMAP sources, you will often get bloating, abdominal pain or diarrhoea. Going slowly with well-tolerated sources usually works better.
How much fibre a day with IBS?
Nutrition societies recommend at least 30 grams a day for adults. With IBS, your individual tolerance matters more than the exact number. Increase in small steps and watch how your stomach reacts.
Is psyllium husk low FODMAP?
Psyllium husk ferments very little and is often well tolerated with IBS. A small starting amount and plenty of water are important. With ready-made products, check that no inulin or other additives have been mixed in.
Does resistant starch help with IBS?
The evidence is still thin. A pilot study from Edith Cowan University suggests that resistant starch is better tolerated together with psyllium husk than on its own. Cooled potatoes or cold rice in small portions are an easy way to start.
Sources: Monash University FODMAP; German Nutrition Society (DGE); Swiss Society for Nutrition (SGE); NICE Guideline CG61, Irritable bowel syndrome in adults; Gunn D. et al., Psyllium reduces inulin-induced colonic gas production in IBS, Gut 2022; Edith Cowan University, pilot study on resistant starch and psyllium husk in IBS.
Photo: Carlee Jones on Unsplash
