Last Updated: 29 January 2023

Psyllium Husk For IBS – Does It Actually Help?

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Psyllium husk may just be the most popular fiber supplement in the world. You probably know it best as Metamucil, which is a brand that uses psyllium in many of their products. But does it help or hinder IBS? Well, in this guide, we'll walk you through all the research on how it might support people with constipation (IBS-C) - and even some research looking at how it might help with IBS in general! Just as importantly, we'll look at dosage amounts based on the latest studies. By the end of this, you'll be a 'Professor of Psyllium' and have a much better idea of whether it might be worth trying for you.
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Table of Contents

Psyllium Husk 101

What Is Psyllium?

Psyllium is a fiber derived from the seed of a plant called Plantago ovata. If you’ve never heard of psyllium before, it could be because it’s sometimes referred to as ispaghula1. If that doesn’t sound familiar either, then maybe you’ve heard of Metamucil, which is probably the most widely used psyllium supplement brand. And while Metamucil may have made psyllium popular in the United States, psyllium has been used for ailments for centuries. 1It also happens to be one of the most studied fibers in IBS and a FODMAP-friendly fiber source.2

How Does Psyllium Work In Your Gut?

The health benefits of psyllium are attributed to its unique set of functional and structural properties; it is a soluble, viscous, gel-forming, water-holding, and poorly fermented fiber. 3In other words, when taking psyllium, it forms a gel that holds onto water as it travels through the GI tract, stays intact, and does not fully ferment in the colon. 3Not all soluble fibers have these functional properties that allow them to travel through the gut in this way.

Benefits Of Psyllium

Is Psyllium Husk For Constipation Or Diarrhea?

Outside of the world of IBS, psyllium is most widely used for aiding in constipation relief. However, psyllium is said to have a “stool normalizing” effect, meaning it softens hard stools in constipation but also firms up loose stools in diarrhea.3

Its primary mechanism for softening stool and acting as a laxative is its gel-forming and water-holding capacity. This increase in the stool’s water content can ease stool evacuation in constipation.1

And while psyllium has been shown to help with firming stool in diarrhea, studies are sparse, and results are mixed.4567

Does Psyllium Husk Work For IBS?

It’s pretty much universally agreed upon that psyllium can be used as an effective treatment for IBS.

  • For instance, the Canadian Association of Gastroenterology (CAG) recommends psyllium for treating IBS8.
  • While other organizations, like the American College of Gastroenterology (ACG) or the British Society of Gastroenterology (BSG), recommend ‘soluble fiber’ for treating IBS – when you dig deeper, the studies referenced are actually based on psyllium.9
  • These organizations came to this conclusion based off the evidence, as psyllium is one of the most studied fiber supplements in IBS.
  • Most recently, 2 meta-analyses concluded that psyllium has a positive effect on IBS symptoms and can be helpful with treating IBS symptoms1011. If ‘postive effect’ sounds a little vague, it’s because it is.

While psyllium is one of the most researched fiber supplements in IBS,  it’s still difficult to make specific recommendations for who should take it, how it may help, or how much you should take. This is because the individual studies have used different methods for measuring symptom improvement, different inclusion criteria, and different dosages, in addition to not studying psyllium’s effect on specific subtypes of IBS.

Even with all that, we can still pretty confidently say that psyllium will improve IBS symptoms in one way or another. And for those of you interested in the specifics, individual studies have shown that psyllium effectively improves things like global IBS symptoms, bowel habits, and constipation.121314

Is Psyllium Husk Recommended For IBS-C?

Although psyllium hasn’t been studied specifically in IBS-C, giving psyllium a try may be a good place to start if you are suffering from constipation 10due to the efficacy seen in non-IBS patients and the evidence that psyllium can improve ‘global IBS symptoms.’

Interestingly a 2009 study did a subgroup analysis of their study subjects who predominantly suffered from constipation and said that 10 g of psyllium had a positive effect, but did not state if it reached statistical significance.18

How To Use Psyllium For IBS

When it comes to dosing psyllium, study amounts have varied from 4g 12to 30 g/day15. Most psyllium supplements offer around 5g of fiber per serving. Our suggestion is always to go slow and drink plenty of water whenever increasing fiber in your diet to decrease the chance of any unwanted GI symptoms. The BSG suggests increasing fiber by 3-4g/day and increase gradually from there16. Of course, whenever starting a new supplement, always talk to your doctor first.

Ultimately, there is very little risk in trying psyllium when used as directed, as study subjects reported few adverse events throughout the various studies. 17So while psyllium may or may not help relieve your IBS symptoms (regardless of subtype), trying it offers a generally safe and easy way to add a low FODMAP fiber source to your diet.


IBS ebook

Which Foods Really Trigger Your IBS?

Discover exactly which foods you should and shouldn’t eat using our IBS Food Journal.

  1. Shah, Aunjum Reyaz MTech; Sharma, Paras PhD; Longvah, Thingnganing PhD; Gour, Vinod Singh PhD; Kothari, S. L.; Shah, Yasir Reyaz MTech; Ganie, Showkat Ahmad PhD. Nutritional Composition and Health Benefits of Psyllium (Plantago ovata) Husk and Seed. Nutrition Today: 11/12 2020 – Volume 55 – Issue 6 – p 313-321 doi: 10.1097/NT.0000000000000450

  2. So D, Gibson PR, Muir JG, et al Dietary fibres and IBS: translating functional characteristics to clinical value in the era of personalised medicine Gut 2021;70:2383-2394.

  3. McRorie, Johnson W. Jr PhD, FACG, AGAF, FACN; Gibb, Roger D. PhD; Sloan, Kyle J. PharmD; McKeown, Nicola M. PhD. Psyllium: The Gel-Forming Nonfermented Isolated Fiber That Delivers Multiple Fiber-Related Health Benefits. Nutrition Today: 7/8 2021 – Volume 56 – Issue 4 – p 169-182 doi: 10.1097/NT.0000000000000489

  4. Smalley JR, Klish WJ, Campbell MA, Brown MR. Use of psyllium in the management of chronic nonspecific diarrhea of childhood. Journal of Pediatric Gastroenterology and Nutrition. 1982 ;1(3):361-363. DOI: 10.1097/00005176-198201030-00014. PMID: 7186049.

  5. Lertpipopmetha, K., Kongkamol, C. and Sripongpun, P. (2019), Effect of Psyllium Fiber Supplementation on Diarrhea Incidence in Enteral Tube-Fed Patients: A Prospective, Randomized, and Controlled Trial. Journal of Parenteral and Enteral Nutrition, 43: 759-767.

  6. N Washington, M Harris, A Mussellwhite, R C Spiller, Moderation of lactulose-induced diarrhea by psyllium: effects on motility and fermentationThe American Journal of Clinical Nutrition, Volume 67, Issue 2, February 1998, Pages 317–321,

  7. Hart, G.K. and Dobb, G.J. (1988), Effect of a Fecal Bulking Agent on Diarrhea during Enteral Feeding in the Critically Ill. Journal of Parenteral and Enteral Nutrition, 12: 465-468.

  8. Paul Moayyedi, MD, Christopher N Andrews, MD, Glenda MacQueen, MD, Christina Korownyk, MD, Megan Marsiglio, MD, Lesley Graff, MD, Brent Kvern, MD, Adriana Lazarescu, MD, Louis Liu, MD, William G Paterson, MD, Sacha Sidani, MD, Stephen Vanner, MD, Canadian Association of Gastroenterology Clinical Practice Guideline for the Management of Irritable Bowel Syndrome (IBS)Journal of the Canadian Association of Gastroenterology, Volume 2, Issue 1, April 2019, Pages 6–29,

  9. Lacy, Brian E. PhD, MD, FACG1; Pimentel, Mark MD, FACG2; Brenner, Darren M. MD, FACG3; Chey, William D. MD, FACG4; Keefer, Laurie A. PhD5; Long, Millie D. MDMPH, FACG (GRADE Methodologist)6; Moshiree, Baha MD, MSc, FACG7ACG Clinical Guideline: Management of Irritable Bowel Syndrome. The American Journal of Gastroenterology: January 2021 – Volume 116 – Issue 1 – p 17-44 doi: 10.14309/ajg.0000000000001036

  10. Ford, Alexander C. MB ChB, MD, FRCP1; Moayyedi, Paul BSc, MB ChB, PhD, MPH, FACG, FRCP, FRCPC, AGAF2; Chey, William D. MD, FACG, AGAF, FACP3; Harris, Lucinda A. MD, FACG4; Lacy, Brian E. MD, PhD, FACG5; Saito, Yuri A. MD, MPH, FACG6; Quigley, Eamonn M. M. MD, MACG, FRCP, FACP, FRCPI7 for the ACG Task Force on Management of Irritable Bowel Syndrome. American College of Gastroenterology Monograph on Management of Irritable Bowel Syndrome. American Journal of Gastroenterology: June 2018 – Volume 113 – Issue – p 1-18 doi: 10.1038/s41395-018-0084-x

  11. Moayyedi P, Quigley EM, Lacy BE, Lembo AJ, Saito YA, Schiller LR, Soffer EE, Spiegel BM, Ford AC. The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis. Am J Gastroenterol. 2014 Sep;109(9):1367-74. doi: 10.1038/ajg.2014.195. Epub 2014 Jul 29. PMID: 25070054.

  12. Prior A, Whorwell PJ. Double blind study of ispaghula in irritable bowel syndrome. Gut. 1987 Nov;28(11):1510-3. doi: 10.1136/gut.28.11.1510. PMID: 3322956; PMCID: PMC1433676.

  13. GEORGE F. LONGSTRETH, DAVID D. FOX, LEE YOUKELES, et al; Psyllium Therapy in the Irritable Bowel Syndrome A Double-Blind Trial, Ann Intern Med. 1981 95, 53-56. doi:10.7326/0003-4819-95-1-53

  14. Ritchie JA, Truelove SC. Treatment of irritable bowel syndrome with lorazepam, hyoscine butylbromide, and ispaghula husk. Br Med J. 1979 Feb 10;1(6160):376-8. doi: 10.1136/bmj.1.6160.376. PMID: 32949; PMCID: PMC1597979.

  15. JALIHAL, A. and KURIAN, G. (1990), Ispaghula therapy in irritable bowel syndrome: Improvement in overall well-being is related to reduction in bowel dissatisfaction. Journal of Gastroenterology and Hepatology, 5: 507-513.

  16. Vasant DH, Paine PA, Black CJ, et al British Society of Gastroenterology guidelines on the management of irritable bowel syndrome Gut 2021;70:1214-1240.

  17. Black, CJ, Yuan, Y, Selinger, CP et al. (4 more authors) (2020) Efficacy of soluble fibre, antispasmodic drugs, and gut–brain neuromodulators in irritable bowel syndrome: a systematic review and network meta-analysis. The Lancet Gastroenterology and Hepatology, 5 (2). pp. 117-131. ISSN 2468-1253

  18. Bijkerk CJ, de Wit NJ, Muris JW, Whorwell PJ, Knottnerus JA, Hoes AW. Soluble or insoluble fibre in irritable bowel syndrome in primary care? Randomised placebo controlled trial. BMJ. 2009 Aug 27;339:b3154. doi: 10.1136/bmj.b3154. PMID: 19713235; PMCID: PMC3272664.

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