Fibre and Diarrhoea: Should You Eat Fibre When You Have Loose Motions?

Diarrhoea is uncomfortable, draining, and often confusing—especially when it comes to food choices. One of the most common questions people ask is:

“Should I stop eating fibre when I have diarrhoea?”

The short answer is no.
The longer, science-backed answer is that the type of fibre you eat matters more than the amount.

Understanding how fibre works can help you manage diarrhoea better and support long-term gut health.

Is Fibre Good for Diarrhoea?

Yes—soluble fibre is helpful for diarrhoea, while insoluble fibre may worsen symptoms during active episodes.

Soluble fibre absorbs excess water in the gut, slows digestion slightly, and helps stools become more formed. Insoluble fibre, on the other hand, speeds up bowel movements, which can make loose motions worse.

This distinction is especially important for people dealing with chronic diarrhoea, IBS with diarrhoea (IBS-D), or sensitive digestion.

Understanding Fibre: Soluble vs Insoluble

Soluble Fibre – The Gut-Friendly Choice

Soluble fibre dissolves in water and forms a gentle gel in the digestive tract. This gel helps regulate stool consistency and supports healing of the gut lining.

Common soluble fibre foods include:

Oats and oat porridge
Psyllium husk (isabgol)
Ripe bananas
Apples without the skin

Research shows that soluble fibre is fermented by healthy gut bacteria to produce short-chain fatty acids, which help the colon absorb water and maintain a healthy gut barrier.

You can read more about how fibre supports digestion in our gut health and digestion guide.

Insoluble Fibre – Best Limited During Diarrhoea

Insoluble fibre adds bulk and increases the speed at which food moves through the intestines. While this is useful for constipation, it can aggravate diarrhoea.

Foods high in insoluble fibre include:

Bran and wholegrain cereals
Raw vegetables and salads
Nuts and seeds

During diarrhoea flare-ups, these foods are best reduced temporarily, then reintroduced gradually once symptoms improve.

How Soluble Fibre Helps Control Diarrhoea

Soluble fibre works in several important ways:

Absorbs excess fluid in the intestines
Improves stool consistency
Feeds beneficial gut bacteria
Supports gut lining repair
Helps normalise bowel movement frequency

Clinical studies show that diets including soluble fibre can reduce diarrhoea frequency and severity, particularly in people with long-term or medically related diarrhoea.

This makes soluble fibre a key part of evidence-based nutrition strategies for digestive health.

Fibre Intake in Chronic Diarrhoea

Chronic diarrhoea (lasting more than four weeks) often involves inflammation, nutrient malabsorption, and disruption of the gut microbiome.

Completely avoiding fibre in the long term can:

Weaken gut health
Reduce beneficial bacteria
Make digestion more unpredictable

Studies show that people with chronic diarrhoea often consume less total fibre than those without symptoms. A better approach is gradual introduction of soluble fibre, tailored to individual tolerance.

If you experience IBS-related symptoms, our article on IBS and diarrhoea management may be helpful.

Best Fibre Foods to Eat When You Have Diarrhoea

Helpful choices

Oat porridge
Ripe bananas
Peeled apples or applesauce
Psyllium husk (small amounts with plenty of fluids)

Foods to limit during flare-ups

Bran cereals
Wholegrain bread
Raw vegetables
Seeds and nuts

For broader dietary strategies, explore our digestive health resources.

Frequently Asked Questions About Fibre and Diarrhoea

Is fibre bad for diarrhoea?
No. Soluble fibre helps absorb excess water and improve stool consistency. Insoluble fibre may worsen symptoms and should be limited during active diarrhoea.

Which fibre is best for loose motions?
Soluble fibre such as oats, psyllium husk, bananas, and peeled apples is best.

Should I stop fibre completely during diarrhoea?
Not usually. It’s better to reduce insoluble fibre and continue gentle sources of soluble fibre.

Can fibre help IBS with diarrhoea (IBS-D)?
Yes. Research shows soluble fibre, especially psyllium, can help regulate bowel movements in IBS-D.

Key Takeaway

Diarrhoea doesn’t mean your gut wants less care—it needs the right kind of support.

✔ Soluble fibre helps manage diarrhoea and supports gut healing
✔ Insoluble fibre may worsen symptoms during flare-ups
✔ Fibre intake should be gentle, gradual, and personalised

If diarrhoea lasts more than a few weeks, or is accompanied by weight loss, blood, or fatigue, professional medical advice is important.

About the Author

Nanish Malhotra, BSc Human Nutrition
Nutrition Graduate | Evidence-Based Nutrition Educator | Gut Health & Digestive Wellness

Nanish Malhotra is a Bachelor of Human Nutrition graduate with a strong interest in gut health, digestive disorders, and evidence-based nutrition care. With academic training in nutrition science and hands-on experience developing nutrition education resources, Nanish focuses on translating complex research into clear, practical advice for everyday health.

Nanish has worked on nutrition-related projects across clinical nutrition, public health, and food science, including internships with professional dietetic teams and food service settings. His work emphasises science-backed dietary strategies, especially for conditions such as diarrhoea, IBS, nutrient deficiencies, and metabolic health.

Through NM Food Science, Nanish shares research-informed articles, patient education content, and nutrition awareness resources to help people make confident, informed food choices.

Why Trust This Content? (E-E-A-T Signals)

✔ Evidence-Based:
This article is based on findings from peer-reviewed research studies, meta-analyses, and clinical nutrition guidelines, including research published in journals such as Nutrients, Clinical Nutrition, and Journal of Nutrition.

✔ Expertise:
Written by a qualified Human Nutrition graduate with formal education in digestive physiology, dietary fibre, and clinical nutrition.

✔ Experience:
Content is informed by academic training, nutrition internships, and real-world exposure to digestive health education and patient counselling frameworks.

✔ Transparency & Safety:
This article is for educational purposes only and does not replace medical advice. Readers with ongoing or severe symptoms are encouraged to seek professional healthcare support.

✔ Updated & Reviewed:
Content is reviewed regularly to reflect current nutrition science and guideline updates.

Medical Disclaimer

The information provided on this website is intended for general educational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional before making dietary changes, especially if you have chronic diarrhoea, gastrointestinal disease, or other medical conditions.

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