5 Everyday Foods That Could Be Making Your IBS Worse
If you’ve ever eaten a “healthy” meal and ended up doubled over in pain, you know how frustrating IBS can be. You try to do the right thing, but somehow, the foods you think should help your body only make things worse.
That’s because IBS isn’t just about what you eat—it’s about how your body processes food. Certain foods can create extra gas, slow motility, or trigger inflammation, even if they’re perfectly fine for someone else.
In this article, we’ll look at five everyday foods that commonly worsen IBS, why they’re a problem, and what functional medicine suggests as alternatives.
1. Dairy Products
Why it’s a trigger:
Many women with IBS have trouble digesting lactose, the sugar in milk.
In lactose intolerance, the enzyme lactase is low, so undigested lactose ferments in the gut—causing gas, bloating, and diarrhea.
Beyond lactose, some people react to casein (a milk protein) which can worsen gut inflammation.
Research insight: Up to 75% of adults worldwide lose the ability to digest lactose well after childhood (Misselwitz et al., Lancet Gastroenterol Hepatol, 2019). In IBS patients, eliminating or reducing dairy often reduces bloating and pain.
Functional medicine tip:
Try lactose-free milk or plant-based alternatives (almond, oat, or coconut).
If you tolerate dairy fat but not lactose, hard cheeses and butter are often easier to digest.
Test with a 2–3 week elimination trial to see how symptoms change.
2. Wheat and Gluten-Containing Grains
Why it’s a trigger:
Wheat contains gluten, but also fructans (a type of FODMAP carbohydrate). Both can cause trouble.
Gluten sensitivity (not celiac disease) can trigger gut irritation, brain fog, and fatigue.
Fructans ferment in the small intestine, producing excess gas.
Research insight:
Studies show that low-FODMAP diets (which restrict wheat) improve IBS symptoms in up to 70% of patients (Staudacher et al., Gastroenterology, 2017).
Some people improve on gluten-free diets even without celiac disease, suggesting a non-celiac gluten sensitivity connection (Biesiekierski et al., Am J Gastroenterol, 2011).
Functional medicine tip:
Swap wheat for gluten-free grains (rice, quinoa, buckwheat).
Consider a low-FODMAP approach temporarily to identify whether wheat is an IBS trigger for you.
3. Beans and Lentils
Why it’s a trigger:
Beans and lentils are loaded with FODMAPs—particularly galactooligosaccharides (GOS).
They’re healthy foods, but for sensitive guts, they ferment too quickly, creating gas and cramping.
Research insight:
In studies, beans consistently rank as top gas-producing foods for IBS patients (Clemente et al., Nutrients, 2019).
Lentils may be better tolerated if soaked or sprouted to reduce fermentable carbs.
Functional medicine tip:
Try canned beans, which have lower FODMAP levels than dried beans.
Start with small portions—1–2 tablespoons—and increase slowly if tolerated.
Substitute with easier-to-digest proteins like eggs, chicken, or fish (if tolerated).
4. Onions and Garlic
Why it’s a trigger:
These kitchen staples are rich in fructans, a high-FODMAP carbohydrate.
Even small amounts can trigger bloating, especially when eaten raw.
Research insight:
In low-FODMAP studies, onions and garlic are among the most common bloating triggers (Halmos et al., J Gastroenterol Hepatol, 2014).
Yet, they also contain powerful prebiotics that support gut health in people without IBS—highlighting the unique sensitivity IBS patients face.
Functional medicine tip:
Use garlic-infused olive oil or onion-free spice blends to get flavor without the fermentable carbs.
Cooked onions may be easier to tolerate than raw, but many IBS patients still need to limit them.
5. Artificial Sweeteners
Why it’s a trigger:
Sugar alcohols like sorbitol, xylitol, and mannitol are poorly absorbed in the small intestine.
They act like FODMAPs, pulling water into the gut and fermenting rapidly—causing diarrhea, gas, and bloating.
Even some natural sweeteners (like honey or agave) are high in fructose, which can worsen IBS.
Research insight:
Sorbitol and mannitol are recognized gut irritants, especially in IBS populations (Shepherd et al., Am J Gastroenterol, 2008).
Even small amounts of sugar alcohols can create significant discomfort in sensitive guts.
Functional medicine tip:
Avoid “sugar-free” gums, candies, and diet products with sugar alcohols.
Opt for maple syrup, monk fruit, or stevia in moderation if you need a sweetener.
Putting It All Together
If these five food groups are common triggers, does that mean you can never enjoy pizza, hummus, or a latte again? Not necessarily.
Functional medicine emphasizes bio-individuality—meaning everyone’s gut is unique. What inflames one person may be tolerated by another. The key is to:
Identify your triggers through elimination and reintroduction.
Support digestion with enzymes, probiotics, and gut-healing nutrients.
Restore balance so that, over time, your gut becomes more resilient and flexible.
Real-Life Example
Jessica, a 29-year-old patient, loved her daily yogurt parfait and veggie-packed lunch bowls. But she constantly felt bloated.
Testing and food journaling revealed:
Dairy intolerance (bloating after yogurt and cheese).
Onion sensitivity (cramping within 2 hours).
Better tolerance with gluten-free grains and cooked vegetables.
By removing dairy and onions for six weeks, adding probiotics and digestive enzymes, her bloating improved by 75%. Later, she was able to reintroduce small amounts of cheese without issue.
Takeaway
IBS isn’t about following a rigid “good vs. bad” food list. Instead, it’s about uncovering which foods challenge your system, healing your gut, and reintroducing what you can tolerate.
Dairy, wheat, beans, onions, and artificial sweeteners are among the most common IBS culprits—but with a structured plan, you can reduce symptoms without living in constant fear of food.
👉 At Bluegrass Natural Health, we help women 25–55 uncover their unique food triggers, heal their gut, and restore food freedom. If bloating, cramping, or food fear is running your life, book a free discovery call today to begin your healing journey.
📚 Selected References
Misselwitz B et al. (2019). Lactose intolerance. Lancet Gastroenterol Hepatol, 4(8): 730–746.
Staudacher HM et al. (2017). Low FODMAP diet in IBS. Gastroenterology, 152(5): 1358–1364.
Biesiekierski JR et al. (2011). Gluten causes GI symptoms in non-celiac individuals. Am J Gastroenterol, 106(3): 508–514.
Clemente JC et al. (2019). Fermentation and gut symptoms. Nutrients, 11(7): 1631.
Halmos EP et al. (2014). FODMAPs and IBS. J Gastroenterol Hepatol, 29(2): 236–243
Shepherd SJ et al. (2008). Sugar alcohol malabsorption in IBS. Am J Gastroenterol, 103(12): 3112–3118.