IBS and Foods to Avoid

You enjoy a normal dinner. An hour later, your stomach cramps and bloats. Was it the pasta, the garlic, or the second coffee? If you have irritable bowel syndrome (IBS), you know the guessing game.

There is no single list of IBS foods to avoid that fits everyone. Most people with IBS link their symptoms to what they eat (1), but the triggers differ from person to person. Common ones include onions and garlic, beans, wheat, dairy, certain fruits, sugar-free sweeteners, fatty food, caffeine, alcohol, and spicy dishes. The goal is to find your own triggers, not to cut out everything.

This article is for people with an IBS diagnosis and for anyone who suspects they have it. Only a doctor can diagnose IBS. It is part of our complete guide to bloating and gas.

written and reviewed by Anouk Martini (registered dietician)

In short

Most people with IBS link their symptoms to food, but triggers are personal (1).
Common triggers are FODMAP-rich foods such as onions, garlic, beans, wheat, and certain fruits, plus fatty food, caffeine, alcohol, and spicy dishes.
The low FODMAP diet is a short, structured trial and not a way of eating for life. Guidelines recommend a limited trial (2).
Many foods are usually well tolerated, such as rice, eggs, carrots, and bananas. Soluble fiber has the best evidence in IBS (1).
A restrictive diet is not right for everyone, so involve a dietitian or doctor (1).

Which foods should you avoid with IBS?

It depends on you. The foods that most often trigger symptoms are those rich in FODMAPs, plus fatty, spicy, and caffeinated foods and alcohol. Because most people with IBS notice a link between food and symptoms (1), a food diary works better than any generic list. Use the list below as a starting point, not as a list of forbidden foods.

What are the most common IBS trigger foods?

These ten are not the worst foods for everyone. They are the ones that come up most often. Several are FODMAPs, carbohydrates that are poorly absorbed in your small intestine and fermented by bacteria in your colon (3).

1. Onions and garlic

Both are very rich in fructans, a type of FODMAP. Even small amounts bother some people, which makes them hard to spot in sauces, soups, and seasoning mixes.

2. Beans and lentils

Legumes contain galacto-oligosaccharides (GOS) and fructans. Small portions are often easier to handle than a big bowl of chili.

3. Wheat, rye, and barley

These grains contain fructans. Some people who feel better without bread and pasta may be reacting to fructans, not gluten. The evidence for gluten-free diets in IBS is mixed (1).

4. Dairy products with lactose

Milk, ice cream, and soft cheeses contain lactose. Butter and many cheeses are naturally low in lactose, so you do not have to drop all dairy (4). Read more about lactose.

5. Certain fruits

Apples, pears, mangoes, watermelon, and stone fruits contain excess fructose, polyols, or both. Fruit juice and dried fruit pack a lot of sugar into a small serving.

6. Sugar-free products

Sorbitol, mannitol, and xylitol are sugar alcohols (polyols) found in sugar-free gum, candy, and protein bars. They are poorly absorbed and can cause gas and loose stools.

7. Fatty and fried foods

Fried food, cream sauces, and fast food are heavy to digest. For some people, a big fatty meal sets off cramping.

8. Coffee and other caffeine

Caffeine can speed up your gut. If coffee sends you running to the bathroom, try smaller cups, decaf, or herbal tea.

9. Alcohol

Alcohol can irritate your gut. Mixers made with fruit juice or sweeteners can add FODMAPs on top.

10. Spicy food

Hot peppers can cause burning, cramping, or urgency in some people. Start with milder spices and see how you feel.

What can you eat with IBS?

Many foods are usually well tolerated with IBS. Think plain proteins, rice, potatoes, most vegetables, firm bananas and berries, and lactose-free dairy. Tolerance still differs per person, and the Monash University FODMAP app rates foods as low, moderate, or high in FODMAPs (4).

Protein: eggs, chicken, turkey, fish, and firm tofu.
Grains and starches: rice, oats, quinoa, and potatoes.
Vegetables: carrots, zucchini, cucumber, spinach, bell peppers, and green beans.
Fruit: firm bananas, blueberries, strawberries, oranges, kiwi, and grapes.
Dairy: lactose-free milk and yogurt, butter, and many cheeses (4).
Nuts and seeds: macadamias, peanuts, and most seeds. Cashews and pistachios are higher in FODMAPs (4).

Serving size matters. A food can be fine in a small portion and a trigger in a large one.

Does fiber help or hurt with IBS?

It depends on the type. Soluble fiber, found in oats, psyllium husk, and some fruits and vegetables, is effective for overall IBS symptoms (1). Coarse insoluble fiber, such as wheat bran, bothers some people. Add fiber slowly and drink enough fluids. Fiber and gas are closely linked, so read our article on foods that cause gas.

Should you try a low FODMAP diet?

A limited trial can help many people with IBS. The American College of Gastroenterology (ACG) guideline recommends it (2), and the American Gastroenterological Association (AGA) calls it the most evidence-based diet for IBS (1). It has three phases: restriction for no more than 4 to 6 weeks, step-by-step reintroduction, and a personal plan based on what you learn (1).

Do it with a registered dietitian when you can (1).
Set an end date. If nothing improves after the trial, stop and talk to your doctor about other options (1).
Do not skip reintroduction. The goal is a varied diet, not a long list of forbidden foods.
A restrictive diet is not a good fit for everyone, for example if you already eat a limited variety, are at risk of malnutrition, or have an eating disorder (1).

You can read more in our FODMAP guide.

How do you find your own trigger foods?

Start simple and change one thing at a time:

Keep a food and symptom diary for two weeks. Write down what you eat, when symptoms start, and how stressed you were.
Eat at regular times and take your time at the table.
Try our intolerance test. It takes about two minutes and gives an indication of which food components may play a role for you: lactose, fructose, fructans, galactans, polyols, sucrose, starch, and histamine. It does not test for gluten or cow’s milk protein allergy, and it does not replace a diagnosis.
Take your diary and your results to your dietitian or doctor.

What does a digestive enzyme blend like Fodmix do?

Digestive enzymes are proteins that help break down food. Lactase splits lactose into glucose and galactose in the small intestine. The enzyme alpha-galactosidase splits galactans, such as the raffinose in beans. Enzyme supplements provide specific enzymes that you take with a meal.

Fodmix (Quatrase 10,000) is an enzyme blend developed by our in-house dietitians. It contains Alpha Galactosidase (1200 u), Xylose Isomerase (7500 u), Lactase (10,000 FCC), and Invertase (500 u). Fodmix helps reduce occasional gas, bloating, and discomfort, allowing you to enjoy meals without restrictive diets.*

The capsules are easy to twist open, so you can take the powder separately or mix it with water. Fodmix is suitable for children aged 2 and up, vegan, and free of gluten and soy. It is Low FODMAP Certified™ by Monash University.

*This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

When should you talk to a doctor or dietitian?

Only a doctor can diagnose IBS. A doctor can often do this from your symptoms, and may also check for celiac disease or inflammation if diarrhea is a main symptom (2).

Do your symptoms persist, are you losing weight without trying, or are you cutting out more and more foods? Talk to your doctor or a dietitian. You can also ask our dietitians a question.

Not sure where to start? Our dietitians are happy to think along with you. You can also use the product guide to see which supplement fits your situation:

Sources

Chey WD, Hashash JG, Manning L, Chang L. AGA clinical practice update on the role of diet in irritable bowel syndrome: expert review. Gastroenterology. 2022;162(6):1737-45.e5. doi:10.1053/j.gastro.2021.12.248
Lacy BE, Pimentel M, Brenner DM, Chey WD, Keefer LA, Long MD, et al. ACG clinical guideline: management of irritable bowel syndrome. Am J Gastroenterol. 2021;116(1):17-44. doi:10.14309/ajg.0000000000001036
Staudacher HM, Whelan K. The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut. 2017;66(8):1517-27. doi:10.1136/gutjnl-2017-313750
Monash University. High and low FODMAP foods [Internet]. Melbourne: Monash University FODMAP. Available from: https://www.monashfodmap.com/about-fodmap-and-ibs/high-and-low-fodmap-foods