Confession: back while I was in the trenches with irritable bowel syndrome (IBS), I dabbled in a gluten-free diet for YEARS before I finally cracked my IBS code. (Don’t get me wrong – going gluten free did help me quite a bit! But it wasn’t enough as a stand-alone intervention.)
I know I’m not the only one who’s had an experience like that! (AKA, you feel somewhat better going gluten free from an IBS symptoms standpoint – but not 100%. There’s more to the story.)
If you’re considering going on a gluten free diet for IBS, or you’re currently gluten free in hopes of finding complete (and lasting) IBS symptom relief, keep reading.
In this article I’ll reveal the potential pros, blind spots and clinical contraindications of a gluten free diet, when it comes to managing and resolving IBS symptoms.
Disclaimer: This article was written for general education purposes, to help complement and enhance (but not replace) medical and nutritional advice from your healthcare team. Please consult with your doctor and a gut health dietitian nutritionist 1-1 for customized recommendations.
Table of Contents
The key takeaways
- Some people who are diagnosed with IBS may benefit from a gluten free diet if their IBS symptoms are actually caused by an underlying autoimmune condition called celiac disease,
- Many people with IBS (but not celiac disease) may STILL feel better on a gluten free diet if they have a non-celiac gluten intolerance, and/or non-celiac wheat sensitivity.
- Gluten contains gliadin, a protein found to increase zonulin levels in the gut, increasing gut permeability. Eating gluten may worsen or exacerbate leaky gut in folks with an already-compromised gut barrier.
- Many IBS sufferers who feel somewhat better on a gluten free diet (but not 100%) may actually have a fructan intolerance. (I see this a lot in cases of small intestinal bacterial overgrowth which masquerades as IBS!)
- Some people on gluten free diets may still over-consume processed added sugar from gluten free products.
Large quantities of added refined sugars from ultra-processed carbs have been said to feed dysbiotic microbial overgrowth in the gut, worsening the underlying root cause in many IBS cases.
- Many gluten-free foods contain sugar and starch. A gluten-free diet may not be enough if you or your clients have been diagnosed with IBS but actually have an underlying intolerance to sucrose and/or starch (in cases of sucrase-isomaltase enzyme deficiency, which can in some cases be caused by celiac disease left unchecked for too long).
What is gluten?
Gluten is a type of protein naturally found in certain grains, specifically wheat, barley, rye, and triticale.
It’s what gives dough its stretchiness and elasticity, and what makes bread/cake products soft and “doughy” (versus dry and crumbly) from a texture standpoint.
Recommended reading: Wheat vs .Gluten – What’s the Difference?
Which foods contain gluten?
Gluten is naturally occurring in the following grains:
- Wheat (all variations)
- Whole wheat
- Enriched wheat
- “Wheat flour”
- “Wheat gluten”
- Spelt
- Kamut
- Einkorn
- Semolina
- Durum
- etc.
- Barley
- Rye
- Triticale (a cross between wheat and rye)
Gluten is also often found in oats and oat products.
While oats are inherently gluten free, some variations of oats may sometimes contain gluten, but only if they have been cross-contaminated with wheat.
- This means gluten-containing grains such as wheat blew into the oat field thus “contaminating” the oats by making direct physical contact.
Given all of the above, gluten is most commonly found in the following TYPES of foods (unless made gluten free):
- Breads and bread products
- Flour tortillas
- Cereals
- Pasta
- Noodles
- Crackers
- Pancakes and waffles
- Bagels and English muffins
- Pastries
- Cookies
- Cakes
- Desserts made with flour
- Gravies and sauces made with flour
I’ve found in my clinical practice (and on my own IBS healing journey) that many people with IBS (with or without celiac disease) seem to feel better reducing their intake of gluten-containing foods, and this isn’t just their heads.
Let’s now dive deeper into what’s going on here.
What is IBS?
Irritable bowel syndrome (IBS) is a type of functional gut disorder which is characterized by a cluster of symptoms which meet criteria for a certain frequency per week, consistently over the course of at least 6 months, in the absence of a medical condition.
Symptoms
IBS symptoms may include at least 3 of any of the following:
- Constipation
- Diarrhea
- Gas
- Bloating/distention
- Abdominal pain/cramping
- Nausea
- Heartburn/reflux
- Food intolerances and sensitivities
(Read more about IBS here.)
Note that the symptoms for IBS overlap with the symptoms of most other gastrointestinal disorders, such as inflammatory bowel disease, sucrase-isomaltase deficiency, small intestinal bacteria overgrowth (SIBO) and celiac disease.
IBS vs. celiac disease
Celiac disease is NOT the same thing as IBS, but the symptoms can be virtually identical.
IBS is a functional gut disorder, while celiac disease is a type of autoimmune disorder which causes people to get very sick from eating any foods containing (or making contact with) gluten.
The key difference between IBS and celiac disease from a nutrition and diet standpoint is that celiac symptoms are only induced after exposure to gluten and will usually resolve with a 100% gluten-free diet (unless other additional underlying conditions are present).
Gluten-free diet – what it entails
A gluten-free diet can be any type of diet that completely excludes exposure to gluten (along with any foods that have been “cross-contaminated” with gluten, so also eliminating foods that have made physical contact with any surfaces that have touched gluten).
Foods allowed on a gluten-free diet include, but aren’t limited to…
Fruits and veggies
All fruits and vegetables are inherently gluten-free and are allowed on a gluten free diet, unless they were prepared with gluten-containing ingredients.
Grains and starches
Grains and starches provide us with complex carbohydrates for sustained energy throughout the day.
While all starchy veggies are gluten-free, not all grains are gluten-free.
Examples of gluten-free grains, starches, and flours allowed on a gluten-free diet include, but aren’t limited to:
- Potatoes (all)
- Squashes (all)
- Corn and corn products
- Cassava flour
- Tapioca flour
- Rice (all types) and rice flour products
- Amaranth
- Buckwheat
- Millet
- Quinoa
- Almond flour
- Coconut flour
- Tiger nut flour
- Nut flours
- Chickpea and lentil flour pastas
- Certified gluten-free oats and oat flour
Fats
All types of fats are allowed on a gluten free diet unless they’re prepared with gluten. Examples of fat-dominant foods include, but arn’t limited to:
- Avocado
- Nuts and nut butters
- Seeds and seed butters
- Peanuts and natural peanut butter
- Oils (olive, avocado, flax, coconut, etc. – all oils)
- Butter and ghee
- Duck fat
- Beef tallow
- Mayonnaise
- Full-fat dairy (cheese, cream, cream cheese, sour cream, etc.)
Proteins
All protein-dominant foods are inherently gluten-free, unless prepared in a gluten-containing sauce or breaded in gluten-containing flour.
- Beans, lentils, and peas
- Peanut butter
- Tofu
- Eggs
- Dairy (cow’s milk, goat milk, cheese, cottage cheese, yogurt)
- Protein powders
- Chicken
- Turkey
- Fish and seafood
- Pork
- Lamb
- Beef
- Bison
- Venison
- Elk
Sweets
While most types of flour-based desserts contain gluten, there’s still a wide variety of gluten-free sweet treats to choose from on a gluten free diet.
All sugars and sweeteners, dairy, and chocolate/cocoa/cacao powder are gluten free, so the key to a gluten-free dessert is to make sure you’re using gluten free flour (if it calls for flour).
Examples of gluten free sugars, sweets and treats include but aren’t limited to:
- Honey
- Maple syrup
- Coconut sugar
- Dates
- Pudding
- Ice cream (most but not all types)
- Sorbet
- Custards
- Fudge (most but not all types)
- Candy and chocolate (most but not all types)
Weighing the pros and cons of a gluten free diet for IBS: factors to consider
Celiac disease and IBS
In my experience as a gut health dietitian, I’ve seen a certain number of adults who were diagnosed with IBS but who never actually ruled out celiac disease and ended up testing positive for celiac in my clinic.
If you feel close to 100% better on a gluten free diet, in these cases, you don’t have IBS – you have celiac disease – which explains why a gluten free diet resolved your IBS symptoms. 😉
Non-celiac gluten intolerance
If you’re among the many IBS sufferers with a non-celiac gluten sensitivity/intolerance, listen to your body!
Maybe a gluten free diet can serve as a “piece of the pie” when it comes to your healing journey. Or maybe it’s a game-changer. (Or anything in between…)
I’ve also found that people with non-celiac gluten intolerance usually tend to have other types of food intolerances/sensitivities, so this diet may need to be layered with additional modifications.
Either way, you may want to pair your gluten-free diet with holistic gut repair interventions such as a customized 5R protocol (and of course consult with a qualified 1-1 practitioner to support and guide you along the way!) to help rebuild your oral tolerance to gluten.
Wheat sensitivity
In my case, I ended up having a food sensitivity to wheat (based on my MRT food sensitivity test results).
If you have a wheat sensitivity, you may not be able to eat wheat, even if it’s low FODMAP (looking at you, sourdough!).
However, people like me with a wheat sensitivity (but not celiac disease or a fructan intolerance) may potentially still be able to tolerate eat rye and barley (high FODMAP, gluten-containing grains) without reacting.
Gluten and leaky gut
Many of my clients who run a GI MAP or Gut Zoomer test (or something similar) find they have high levels of antibodies to gliadin, indicating an adverse immune response to gluten in their gut.
That’s because gluten contains gliadin, a component of gluten which stimulates the release of zonulin (a protein which causes our tight junctions in the intestinal lining to open wider).
Generally, If you (or your clients) have (or suspect) intestinal hyperpermeability, aka leaky gut, you may benefit from a gluten-free diet although it would not be enough to heal your gut as a stand-alone intervention but rather it could serve as a piece of your holistic gut repair puzzle.
Fructan intolerance
Fructans are a type of fermentable oligosaccharides (the “O” in FODMAP) which happen to be naturally occurring in large quantities in wheat, barley, and rye – the three primary food sources of gluten in the diet.
Going on a gluten-free diet may provide some significant relief if you’re an IBS sufferer prone to fructan intolerance – not because of the gluten, because it cuts out three primary food sources of fructans (which coincidentally also happen to contain gluten).
However, fructans are not exclusively in gluten-containing grains. (This is a blind spot of the gluten free diet when it comes to IBS symptom management!)
- For example, fructans are also naturally occurring in some gluten-free foods like garlic and onions.
So, a low fructan/low FODMAP elimination diet may be more holistic and beneficial than a gluten-free diet for folks who are reacting to the fructans (versus the gluten) in wheat, barley and rye.
Added sugar and ultra-processed carbs
A lot of gluten-free diets can still be high in added sugar and ultra-processed carbs, which have bene shown in many cases to feed overgrowth of dysbiotic (functionally pathogenic) gut microbes linked with IBS and autoimmune disease.
(Think: candy, ice cream, gluten free cupcakes, gluten free cookies, etc… a lot of stuff we see in the Standard American Diet!)
If your gluten free diet isn’t nutritionally balanced and/or it is too high in refined carbs/added sugars, which are pro-inflammatory, your gut won’t heal as quickly/easily even if gluten is a trigger for you.
Sucrose and starch intolerance
There are some tricky cases where people are diagnosed with IBS… but they actually have a sucrase-isomaltase enzyme deficiency, causing a sucrose intolerance and/or starch intolerance.
(Ironically, leaving celiac disease unchecked for too long can actually cause this as a complication!)
This is tricky because while gluten-containing foods are all triggers (because they all contain starch), a lot of gluten free foods still contain sucrose and starch – so a gluten free diet won’t provide relief in these cases,
In cases of an underlying sucrase-isomaltase deficiency, which can trigger diarrhea after eating sugar and starch, a gluten free diet would not be enough to feel better. (You’d need a low sucrose, low maltose diet.)
As you can see, there’s a LOT to consider and everybody is different!
In addition to working with an expert, keeping an IBS food diary may help you to identify food-symptom triggers and patterns more quickly.
Frequently asked questions (FAQs)
Is gluten a FODMAP?
No; gluten is not a FODMAP. FODMAPs are fermentable carbohydrates, and gluten is not a carbohydrate but rather a protein found in some grains containing fermentable carbohydrates.
So, a gluten free diet is not the same thing as a low FODMAP diet. A gluten free diet can still contain FODMAPs, and a low FODMAP diet can still contain gluten (although it’s usually lower quantities compared to a regular diet).
What’s the difference between gluten vs. starch?
While both gluten and starch are found in grains such as wheat, barley, and rye, gluten is a protein while starch is a complex carbohydrate.
Starch is found in all grains, even gluten free grains, as well as in starchy vegetables like corn and potatoes.
Is a gluten intolerance the same thing as a FODMAP intolerance?
No, a gluten intolerance is not the same as a FODMAP intolerance although there is some overlap in terms of trigger foods and symptoms.
Both gluten intolerance and FODMAP intolerance may trigger similar types of IBS symptoms.
From a nutrition standpoint, people with a gluten intolerance may feel better on a gluten free diet while people with a FODMAP intolerance would not. That’s because many gluten-free foods are high in FODMAPs.
(Read more about FODMAP intolerance here!)
Gluten intolerance vs. IBS – how do I know which I have?
Many people can have both a gluten intolerance and IBS; however, if you exclusively have a gluten intolerance (but not IBS) you may find more complete relief on a gluten-free diet.
If you also have IBS, you may find that a gluten-free diet is not enough to manage/resolve your unwanted symptoms.
What’s the difference between gluten vs. fructans?
Both gluten and fructans are found in wheat, barley, and rye – but they are very different constituents!
Gluten is the protein that gives these grains their elasticity. Fructans are small, poorly digested carbohydrates which are generally more likely to ferment in our intestines, leading to symptoms like gas/bloating, diarrhea, etc… especially in IBS sufferers.
While gluten is exclusively found in just a few specific grains, fructans may also be found in gluten-free foods like garlic and onions to name a few.
Gluten vs. wheat – which is more important for IBS?
The answer to this question totally depends on your biochemical individuality!
But generally, if you’re brand new to uncovering which foods work best (and which foods don’t work well) for your body, you may want to first rule out celiac disease before cutting gluten or wheat out of your diet.
(I explain why this is important in my free gut guide, which unpacks 5 common diet mistakes to avoid when healing your gut, here!)
Once you’ve ruled out celiac disease, you may benefit from exploring a low FODMAP elimination diet or a gluten free elimination diet, depending on what your food-symptom journal reveals to your 1-1 healthcare team.
Related articles & recommended reading
- What’s the Best IBS Diet for You? (Expert Guidance)
- IBS and Coffee – Can They Co-Exist?
- What’s the Best Sweetener for IBS?
- IBS and Sugar – A Holistic Perspective
- What’s the Best Milk for IBS Sufferers? (Gut Health Dietitian Picks)
- Tomatoes, IBS, Gut Health and Immunity: What You Should Know (Beyond FODMAPs)
- Why and How to Keep an IBS Food Diary
Recap & big-picture takeaways
Gluten isn’t inherently bad, but I believe a significant percentage people with IBS seem to feel at least *somewhat* better on a gluten free diet.
This can be attributed to a variety of possible factors, such as:
- Undiagnosed celiac disease (mis-diagnosed as IBS)
- Non-celiac gluten intolerance
- Fructan intolerance
- Non-celiac wheat sensitivity
Folks who may NOT feel better on just a gluten-free diet for IBS include those with the following conditions:
- Sucrase-isomaltase deficiency (with subsequent sucrose intolerance and sometimes a starch intolerance)
- IBS caused by dysbiosis or fungal overgrowth in the gut
- Multiple FODMAP intolerances or other intolerances (sulfur, histamine, etc.)
Keeping a detailed IBS food diary (type of food-symptom journal) may help you to identify trigger food patterns more easily.
Ultimately working 1-1 with a qualified expert who can provide clinical and holistic guidance will be the fastest way to crack your IBS code.
Next steps
Keep learning from me
If the info in this article resonates with you, there’s more where that came from. (This stuff is my jam!)
Feel free to download my free guide where I reveal the 5 most common IBS diet mistakes to avoid (and what to do instead).
Let’s work together
Hey, IBS sufferer: Would you like to be guided 1-1 by an expert who has been in the trenches (and made it out on the other side), so you don’t have to go through it the hard way?
If you live in the U.S., I’d love to be a part of your healing journey!
Should you choose to apply for 1-1 services (here), someone from my team will reach back out with info and details on next steps if it feels like a great mutual fit.
There is hope for you. This ishh IS figureoutable – for those who keep going. Don’t give up!
Sending you love and wishing you all the best!
XX – Jenna
