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What Are the Worst Foods for IBS? 13 To Avoid (and Some to Eat More of)

Are you sick of suffering from stomach problems like Irritable Bowel Syndrome? Your diet deserves most of the blame. The symptoms of a badly behaved gastrointestinal tract will affect every aspect of your life, so it’s smart to take the time to determine what’s triggering your problems in the first place. Then you can change your lifestyle in crucial ways to calm down your digestive system and keep things functioning as they should.

But why do you have IBS to begin with? Let’s look at the details.


What is IBS?

Irritable bowel syndrome (IBS) is a broad classification used for recurring problems with your bowels and digestive system. Classic symptoms include regular bouts of cramping, bloating, diarrhea, constipation, and flatulence. In most cases, IBS is a chronic disease that can’t be cured. Instead, it needs to be managed over time.

If you have IBS, you’re not as alone as you think. The American Journal of Gastroenterology estimates that between 10-15 percent of people with stomach problems who live in industrialized countries are suffering from IBS. In many cases, eating a western diet is primarily to blame.

Digestive discomfort isn’t something you should ignore. One of my health professors used to say  that, “life and death both begin in the bowel”and I have taken this lesson to heart in my functional medicine practice. I believe that your gut is the foundation of good health, and keeping it in working order will affect every other aspect of your life. For instance, more than 75% of your immune system is located in your gut, meaning that compromising its functioning will raise your risk of developing other diseases.

Do you have IBS? Some of the common symptoms include:

  • Frequent trips to the bathroom
  • Abdominal pain or cramping
  • Chronic bloating and gassiness
  • Mucus in stools
  • Alternating between diarrhea and constipation on a regular basis

What are the Biggest Triggers for IBS?

IBS Causes

It’s still not known what causes IBS. Some factors that seem to play a role include muscle contractions within the intestine, chronic inflammation, an untreated infection that festers over time, and changes with the bacteria levels within the digestive system.

While doctors are still learning more about IBS every day, what we do know is that certain lifestyle factors can trigger the condition. For instance, stress and anxiety are known to make stomach problems worse, and taking medications like antibiotics, antidepressants, and medicine produced with sorbitol (like cough syrup) can trigger IBS symptoms. Many women experience worse IBS symptoms during their period as well. You can learn more about my take on the primary causes of IBS on my blog here.

That being said, one lifestyle factor makes a bigger difference in the prevalence of IBS symptoms than any other: your diet.

Top 13 Foods to Avoid for IBS Relief

Since IBS is defined as problems within your digestive system, it only makes sense that the food you eat will make a difference in your symptoms. While the condition is different for everyone, certain foods seem to lead to the biggest flare-ups. Your personal triggers might be different, but if IBS is interfering with your life, eliminating these foods from your diet will reduce its effects.

Worst Foods for IBS

1. Fried foods

You don’t need a doctor to tell you that eating fried foods isn’t healthy, but that doesn’t stop greasy appetizers from being a staple in standard western diets. However, fried food’s high-fat content makes it hard for IBS sufferers to digest, so a better option all around is to seek out grilled or baked alternatives instead.

2.  Gluten

Gluten intolerance might be an overused buzzword today, but it’s also a real condition that causes digestive problems for untold numbers of people. Gluten is a protein, and some people are naturally sensitive or even allergic to it. This can lead to Celiac disease, diarrhea, constipation, and other unpleasant stomach problems. Some evidence also links untreated gluten sensitivities and your likelihood of developing IBS over time.


3. Insoluble fiber

Fiber is what adds “bulk” to your diet. Eating whole grains and fruits and vegetables adds healthy fiber to your digestive system- but these foods can also cause problems for people with IBS. Insoluble fiber (the kind you can’t digest) can trigger diarrhea, so take foods like wheat bran, flax seeds, shredded wheat, and anything with whole wheat off the menu until you determine whether they’re triggering your symptoms.

Best Fiber for IBS

4. Dairy

There are three main reasons why dairy might mess with your digestive system. For starters, its high-fat content can trigger diarrhea (switching to low-fat or no-fat dairy might help). Second, undiagnosed lactose intolerance is a common cause of IBS.

Finally, the pasteurization process creates inflammatory molecules that are hard to digest. Consider cutting dairy out of your life and try sticking to plant-based alternatives like almond milk instead, and you’ll see how your system responds to life without lactose.

If your symptoms aren’t severe, you might be able to incorporate aged cheeses or unpasteurized dairy products back into your diet, as these have considerably less lactose than fresh milk or soft cheeses.

dairy information

5. Sweeteners and Sugar-free Sweeteners

Adverse effects artificial sweetner

Human bodies don’t do well with excessive sugar, and everything from honey to agave nectar and high fructose corn syrup can add hard-to-digest carbs to your diet, which often trigger IBS symptoms. You aren’t any safer with artificial sweeteners, as sorbitol, xylitol, aspartame, and sucralose are also difficult for your body to absorb. Many sugars will also ferment in your stomach, which leads to gas and bloating as the bacteria feast on them.

6. Beans and legumes

Though beans are a stellar source of both protein and fiber, they are well deserving of their reputation as a flatulence producer. Consuming excessive amounts can trigger gas, bloating, and cramps- especially if you already are susceptible to IBS.


7. Caffeinated Drinks

Coffee with Milk

Morning coffee might be necessary for getting your system started each day, but all caffeinated drinks have the potential to stimulate movement in your colon, which can occasionally trigger diarrhea if you already have problems with your digestive system.

8.  Processed foods

There’s little reason ever to consider eating processed foods, but IBS sufferers can add another adverse side effect to the list- if they often contain additives that trigger IBS flare-ups. Likewise, processed foods often include sky-high fat levels, which can clog you up and cause health problems.

9. Chocolate

When it comes to IBS, the caffeine, lactose and sugar content in a chocolate bar creates the perfect storm for digestive problems. Sensitive stomachs should best avoid indulging in this treat if you think chocolate is contributing to your gut problems. Some people can still handle dark chocolate (75% cacao or higher) because it contains less sugar and dairy, so listen to your body to see what works for you.  

10.  Alcohol

The ways your body digests the ingredients in alcoholic drinks can contribute to IBS symptoms. For instance, most beers contain gluten, and wine and mixed drinks are filled with sugar.

Binge drinking poses the most risk, as it can lead to IBS symptoms like nausea, diarrhea, and stomach pain. Likewise, alcohol itself is dehydrating, which can trigger issues with digestion and your liver functioning. If you want to reduce the symptoms of IBS, it’s best to forgo alcohol altogether or to select gluten-free beers or drinks mixed with plain seltzer, not sugary sodas. For some people, tequila or potato-based vodkas can be tolerated by their digestive system.


11. Garlic and Onions

As flavourful as they can make your food, garlic and onions are difficult for your body to break down- which triggers gas production because they are part of the FODMAPS family. Many people with IBS experience painful gas and cramping when eating garlic and onions, regardless of whether they are cooked or raw.

High FODMAPs to avoid

12.  Broccoli and Other Cruciferous Vegetables

Broccoli might be brimming with health benefits, but this superfood is difficult for your digestive system to break down. It often acts as an IBS trigger by generating gas and constipation if you over consume. If you’re unwilling to give up your broccoli habit, consider grating it into small pieces to marginally improve the digestive process.

13. High Fructose Fruits

All fruits by definition contain fructose, but some contain more of this IBS-triggering compound than others. If you want to alleviate your IBS symptoms, consider reducing your consumption of apples, pears, watermelon, fruit juice, and dried fruit.

Bonus: The Best Eating Strategies for Fighting IBS Symptoms

The list is long of the foods that you should avoid for IBS relief. But here’s the good news- plenty of other foods will improve your symptoms and lead to better health overall. Below are some tips for the ways you should eat to help your digestive system function as it should.

  • Drink plenty of plain water each day to keep your system hydrated.
  • Stick with soluble fiber in your meals each day, including oats, brown rice, and whole-grain pasta.
  • Don’t eat contrasting temperature foods in the same meal (such as an icy drink with a hot bowl of soup).
  • Keep portions small and eat regularly throughout the day.
  • Fill up on low-FODMAP fruits like blueberries, bananas, cantaloupe, strawberries, citrus, and grapes.
  • Eat easily digestible, nutrient-dense vegetables like carrots, green beans, sweet potatoes, spinach, and eggplant.
  • Stick with yogurt for your primary source of dairy so that you get both calcium and probiotic benefits for better digestion.  
  • Switch out the butter in recipes and use olive oil instead.

IBS Relief at The Dempster Clinic- Center for Functional Medicine

IBS might be a chronic condition, but that doesn’t mean that you have to live with its side effects. At The Dempster Clinic- Center for Functional Medicine, I can work with you to address any concerns (dietary or otherwise) that you have to improve the functioning of your digestive system.

I am pleased to offer a Complimentary 15-minute Discovery Session for all potential patients. This session can take place over the phone or at the clinic in person. It provides an opportunity for you to learn more about the services I offer and how they can be of benefit to you.  

Please schedule an appointment today! Your best health awaits.

Dr. John Dempster

The Dempster Clinic –

Center for Functional Medicine