Fibre for constipation is the most repeated advice in gut health — and fibremaxxing is having a real moment right now. I’m all for it. Increasing your fibre intake can genuinely support your microbiome, not just your bowel movements.

But “eat more fibre” isn’t universal advice. For a specific group of people — those with SIBO, IMO, pelvic floor dysfunction, or slow transit constipation — more fibre doesn’t just fail to help. It can make things worse.

In this episode, I break down exactly who fibre can backfire for, why it happens, and what the research actually shows. If you’ve increased your fibre, done everything “right,” and either nothing’s changed or you’ve felt worse — this episode explains why that’s not failure. It’s information.

What This Fibre for Constipation Episode Covers

✔ Why fibre works through more than fermentation — and why fluid intake changes how well it works

✔ How fermentable fibre can worsen symptoms in SIBO and IMO, and what the strongest evidence actually shows

✔ Why I don’t believe in long-term fibre or FODMAP restriction

✔ The surprising, evidence-backed link between pelvic floor dysfunction and SIBO

✔ Why fibre response in slow transit constipation is so individual — and why it’s not black and white

✔ The red flags that mean ongoing constipation needs proper medical investigation, not more fibre

Who This Episode Is For

• You’ve increased your fibre intake and either nothing’s changed, or you’ve felt worse
• You have SIBO, IMO, or suspect methane might be part of your constipation picture
• You’ve been diagnosed with, or suspect, pelvic floor dysfunction or dyssynergic defecation
• You have slow transit constipation and want to understand why fibre response varies so much
• You want a nuanced, evidence-based take on “fibremaxxing” rather than a blanket rule either way

Listen to the Full Episode

This episode walks through the actual mechanisms, the research, and what to do next if fibre isn’t working for you — all grounded in the evidence, not blanket rules.

• ▶️ YouTube
• 🎙 Apple Podcasts
• 🎙 Spotify

Research referenced in this episode:

1. Anti M, Pignataro G, Armuzzi A, et al. Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation. Hepatogastroenterology. 1998;45(21):727-732.
2. Bijkerk CJ, Muris JW, Knottnerus JA, Hoes AW, de Wit NJ. Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. Alimentary Pharmacology & Therapeutics. 2004;19:245-251.
3. Halmos EP, Power VA, Shepherd SJ, Muir JG, Gibson PR. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67-75.
4. Huaman JW, Mego M, Bendezú A, Monrroy H, Samino S, Accarino A, Saperas E, Azpiroz F. Correction of Dyssynergic Defecation, but Not Fiber Supplementation, Reduces Symptoms of Functional Dyspepsia in Patients With Constipation in a Randomized Trial. Clinical Gastroenterology and Hepatology. 2020;18(11):2463-2470.
5. Huaman JW, et al. Effectiveness of a high fiber diet in improving constipation in patients with defecatory dyssynergy under treatment with anorectal biofeedback. Exploratory, randomized clinical trial.
6. Damianos JA, Matar A, Halawi H, Wang XJ, Camilleri M. Dyssynergic Defecation Is Associated With Small Intestinal Bacterial Overgrowth. Neurogastroenterology & Motility. 2025;37:e70205.
7. Voderholzer WA, Schatke W, Mühldorfer BE, Klauser AG, Birkner B, Müller-Lissner SA. Clinical response to dietary fiber treatment of chronic constipation. American Journal of Gastroenterology. 1997;92(1):95-98.
8. Xu L, Yu W, Jiang J, Li N. Clinical benefits after soluble dietary fiber supplementation: A randomized clinical trial in adults with slow-transit constipation. Zhonghua Yi Xue Za Zhi. 2014;94(48):3813-3816.
9. Ding C, Ge X, Zhang X, Tian H, Wang H, Gu L, Gong J, Zhu W, Li N. Efficacy of Synbiotics in Patients with Slow Transit Constipation: A Prospective Randomized Trial. Nutrients. 2016;8(10):605.

Connect with gut health naturopath Lynda Griparic: Instagram

As a naturopath with extensive experience in complex gut health conditions, I offer telehealth consultations across Australia and internationally. If you’ve increased your fibre and things haven’t improved — or have gotten worse — self-prescribing can only take you so far. I would love to help you work out why. This is exactly the kind of work I do.

Struggling With Fibre for Constipation? Get Personalised Support [Book a telehealth consultation]

If you have a gut health question you’d like answered or would like to discuss your situation, email info@lyndagriparic.com or leave a comment below.

This content is for educational purposes only and is not intended as medical advice. Please consult your healthcare provider before making any changes to your diet or health routine.