The Problem of Eating Wheat in IBS

Figuring out what to eat when you have intestinal issues like irritable bowel syndrome (IBS) can sometimes be a real challenge. It can make it even more challenging when nutritional science is contradictory.

One of the more confusing subjects of nutritional advice has to do with one of the mainstays of our Western diet—wheat!

We'll look at some of the current research on wheat and IBS, to help you to make an informed decision as to whether or not you should be eating wheat at all.

Wheat bread on a table surrounded by flour
Stefka Pavlova / Getty Images

Before we get into the science, it is important to recognize that most of us are eating wheat in amounts and in ways never seen before. Wheat is traditionally found in bread, pasta, crackers, cookies, cakes, and other baked goods, but wheat products have now found their way into soups, condiments, and even ice cream.

Is Gluten the Problem?

Wheat and all of the many food products made with wheat contain the protein gluten (as do rye, barley, malt, and brewer's yeast).

It is estimated that approximately 5% of people around the world have a gluten-related disorder, which encompasses celiac disease, wheat allergy, and non-celiac gluten sensitivity (NCGS). NCGS is also sometimes referred to as non-celiac wheat sensitivity (NCWS).

Because the symptoms of gluten-related disorders can look very similar to IBS (especially if the IBS has diarrhea as a symptom), the American College of Gastroenterology (ACG) recommends that blood tests for celiac disease be performed in anyone presenting with IBS and diarrhea. The ACG does not recommend routine food allergy testing, citing low sensitivity of allergy tests.

Celiac disease (CD) is an autoimmune disorder, where the body attacks certain intestinal cells in the presence of gluten. Wheat allergy (WA) is a classic allergy where inflammation occurs because of immune globulin E (IgE) being triggered by a component in wheat. Both of these reactions are mediated by our immune systems.

Non-celiac gluten sensitivity (NCGS) is relatively new diagnosis that describes people who experience gastrointestinal or extra-intestinal symptoms after eating foods that contain gluten. NCWS occurs in people who experience these symptoms in the presence of any wheat compound.

Researchers have been conducting studies to see if a subset of IBS patients actually has NCGS instead.

These possible sensitivities would be diagnosed only if they occur repeatedly in the presence of certain foods, and only if CD and WA had been ruled out. The ACG does not think that these sensitivities are an immune response, and they recommend only doing allergy and food sensitivity testing on people who have consistent, reproducible results when exposed to the same food.

Stepping away from gluten for a moment, it should also be noted that there are other compounds within wheat that might play a role in any connection between wheat and IBS symptoms.

Maybe It's a FODMAP Problem

Wheat also contains the carbohydrate fructan. Fructan is one of the fermentable carbohydrates collectively known as FODMAPs that have been shown to exacerbate gastrointestinal symptoms in people who have IBS.

Fructan has been shown to have an osmotic effect within the gut, meaning it increases the amount of fluid, as well as increasing gas production through fermentation by gut bacteria. Both of these qualities are thought to play a role in the IBS symptoms of abdominal pain, bloating, and the motility problems of constipation and diarrhea.

Some researchers theorize that it is fructan sensitivity that is behind what looks like a gluten sensitivity in IBS patients. This hypothesis is based on a small study in which people who had identified themselves as having NCGS reported improvement in their symptoms when placed on a low-FODMAP diet.

Should You Be Eating Wheat at All?

In addition to considering the effect that wheat has on stomach problems, there is the question as to whether or not wheat has negative effects on one's overall health. Most of the wheat that is being consumed in the modern diet has been refined. This means that its bran and germ have been removed.

Refined carbohydrates, such as non-whole-grain wheat, have been linked to the skyrocketing rates of obesity, diabetes, and cardiovascular diseases within our population.

But refined carbohydrates are not the whole picture when it comes to wheat. The U.S. Department of Agriculture recommends the consumption of whole-grain products, including whole-grain wheat, as an important part of a healthy diet.

Whole grains are considered to be nutritionally important due to their fiber content, as well as the fact that they are a source of some important vitamins and minerals.

On the other hand, Paleo diet enthusiasts and the authors of books like ​"Wheat Belly" and ​"Grain Brain" link wheat consumption, whether refined or whole grain, to all sorts of health ills.

Some people assert that eating grain is a relatively new phenomenon, and that our bodies were not evolved to properly digest foods such as wheat. They recommend grain-free diets for optimal health.

They offer evidence that the fiber and vitamin benefits of whole grains have been overblown and that these nutrients can be fully obtained by eating a varied diet of animal and plant foods.

The Bottom Line

The bottom line is that the relationship between wheat consumption and IBS is complex.

As of now, most digestive health experts will agree that although there may be some crossover between IBS, wheat allergy, and NCGS, but most people eat wheat and don't have IBS. Similarly, most IBS patients eat wheat without much problem.

The decision as to whether or not to continue eating wheat is a personal decision and one that is best made with a discussion with your healthcare provider.

If you think your IBS and overall health would benefit from a wheat-free trial, be sure that you have already been tested for celiac disease before trying an elimination diet. An elimination diet is the best way to see if eating wheat does make your IBS symptoms worse.

IBS Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Man
17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. El Khoury D, Balfour-Ducharme S, Joye IJ. A review on the gluten-free diet: Technological and nutritional challengesNutrients. 2018;10(10):1410. Published 2018 Oct 2. doi:10.3390/nu10101410

  2. Shewry P. What Is gluten-Why is it special?Front Nutr. 2019;6:101. Published 2019 Jul 5. doi:10.3389/fnut.2019.00101

  3. Elli L, Branchi F, Tomba C, et al. Diagnosis of gluten related disorders: Celiac disease, wheat allergy and non-celiac gluten sensitivityWorld J Gastroenterol. 2015;21(23):7110–7119. doi:10.3748/wjg.v21.i23.7110

  4. Roszkowska A, Pawlicka M, Mroczek A, Bałabuszek K, Nieradko-Iwanicka B. Non-celiac gluten sensitivity: a review.Medicina (Kaunas). 2019;55(6). doi: 10.3390/medicina55060222

  5. Lacy BE, Pimentel M, Brenner DM, et al. ACG clinical guideline: Management of irritable bowel syndrome. Am J Gastroenterol. 2021 Jan 1;116(1):17-44. doi: 10.14309/ajg.0000000000001036

  6. Sergi C, Villanacci V, Carroccio A. Non-celiac wheat sensitivity: rationality and irrationality of a gluten-free diet in individuals affected with non-celiac disease: a review.BMC Gastroenterology. 2021;21(1):5. doi: 10.1186/s12876-020-01568-6

  7. Barbaro MR, Cremon C, Stanghellini V, Barbara G. Recent advances in understanding non-celiac gluten sensitivityF1000Res. 2018;7:F1000 Faculty Rev-1631. Published 2018 Oct 11. doi:10.12688/f1000research.15849.1

  8. Eswaran S, Goel A, Chey WD. What role does wheat play in the symptoms of irritable bowel syndrome?Gastroenterol Hepatol (N Y).

  9. Okawa Y, Fukudo S, Sanada H. Specific foods can reduce symptoms of irritable bowel syndrome and functional constipation: a reviewBiopsychosoc Med. 2019;13:10. Published 2019 May 8. doi:10.1186/s13030-019-0152-5

  10. Wong WM. Restriction of FODMAP in the management of bloating in irritable bowel syndromeSingapore Med J. 2016;57(9):476–484. doi:10.11622/smedj.2016152

  11. Skodje GI, Sarna VK, Minelle IH, et al. Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivityGastroenterology. 2018;154(3):529–539.e2. doi:10.1053/j.gastro.2017.10.040

  12. Koning F. Adverse effects of wheat glutenAnn Nutr Metab. 2015;67 Suppl 2:8–14. doi:10.1159/000440989

  13. Aune D, Keum N, Giovannucci E, et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2016;353:i2716. Published 2016 Jun 14. doi:10.1136/bmj.i2716

  14. U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans.

  15. Zopf Y, Reljic D, Dieterich W. Dietary effects on microbiota-new trends with gluten-free or paleo dietMed Sci (Basel). 2018;6(4):92. Published 2018 Oct 18. doi:10.3390/medsci6040092

  16. Rej A, Sanders DS. Gluten-free diet and its 'cousins' in irritable bowel syndromeNutrients. 2018;10(11):1727. Published 2018 Nov 11. doi:10.3390/nu10111727

  17. Chey WD. Elimination diets for irritable bowel syndrome: Approaching the end of the beginningAm J Gastroenterol. 2019;114(2):201–203. doi:10.14309/ajg.0000000000000099

Additional Reading

By Barbara Bolen, PhD
Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome.