What Foods Should I Avoid with IBS? A Comprehensive Guide

October 19, 2025 •

4 min read

Up to one in five people experience the symptoms of Irritable Bowel Syndrome (IBS) at some point in their lives, and for many, certain foods are key triggers. Navigating daily meals can be challenging, but understanding what foods should I avoid IBS-related symptoms is the first step toward better digestive health.

Quick Summary

An overview of common food triggers for Irritable Bowel Syndrome, including high-FODMAP items, dairy, gluten, processed foods, and stimulants. This guide provides information to help identify and manage dietary sensitivities.

Key Points

High-FODMAPs: Avoid high-FODMAP vegetables, fruits, grains, and dairy, especially during an elimination diet phase, to reduce gas and bloating caused by fermentation in the gut.
Lactose and Gluten: Many people with IBS are sensitive to lactose in dairy or fructans in wheat, and limiting these can alleviate symptoms like diarrhea, bloating, and pain.
Fatty and Fried Foods: The high-fat content in fried and processed foods can slow digestion and trigger IBS symptoms, particularly diarrhea.
Stimulants and Irritants: Caffeine, alcohol, and spicy foods can irritate the gut and increase bowel motility, worsening symptoms for many individuals.
Read Labels: Artificial sweeteners ending in '-ol' (like sorbitol and mannitol) are high in polyols and can cause digestive distress; check ingredient lists carefully.
Personalization is Key: Since triggers are unique, keeping a food diary is the most effective way to identify your specific sensitivities and tailor your diet accordingly.

Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder that can be significantly impacted by dietary choices. While individual triggers vary, many people with IBS find relief by identifying and limiting certain foods. The most widely recommended approach is the low FODMAP diet, but other food groups and ingredients also commonly worsen symptoms like bloating, gas, abdominal pain, and irregular bowel movements.

Understanding the low FODMAP diet

FODMAPs are fermentable oligo-, di-, and monosaccharides and polyols, which are short-chain carbohydrates that the small intestine doesn't absorb well. When they reach the large intestine, gut bacteria ferment them, causing gas, bloating, and other IBS symptoms. A low FODMAP diet involves a temporary elimination phase, followed by a reintroduction phase, to identify which specific FODMAPs are problematic for an individual. The following are common high-FODMAP foods to avoid, especially during the elimination phase:

High-FODMAP vegetables and legumes

Onions and Garlic: These are notorious for triggering gas and bloating due to fructans, a type of oligosaccharide.
Cruciferous Vegetables: Broccoli, cauliflower, Brussels sprouts, and cabbage contain fructans and other fibers that are difficult for some people to digest.
Legumes and Beans: Chickpeas, lentils, kidney beans, and other legumes are high in galactooligosaccharides (GOS). Soaking and rinsing canned versions may help reduce the FODMAP content.
Other culprits: Asparagus, artichokes, and mushrooms are also high in FODMAPs.

High-FODMAP fruits and sweeteners

Specific Fruits: Apples, pears, watermelon, and cherries are high in fructose and polyols. Dried fruits and fruit juices, which concentrate fructose, should also be limited.
Natural Sweeteners: Honey and high-fructose corn syrup contain excess fructose and are major FODMAP sources.
Artificial Sweeteners: Sugar alcohols like sorbitol, mannitol, and xylitol (often found in sugar-free gum and candy) can cause diarrhea and bloating.

High-FODMAP dairy and grains

Dairy Products: Many IBS patients have lactose intolerance, meaning they lack the enzyme to break down lactose, the sugar in milk. Milk, soft cheeses, ice cream, and custard are often problematic.
Wheat and Rye: These grains contain fructans, and while not all IBS patients have gluten sensitivity, many react to the FODMAPs in these products.

Beyond FODMAPs: Other common triggers

Even if a food is low in FODMAPs, other factors can still trigger IBS symptoms. Keeping a food and symptom diary is vital for identifying personal sensitivities.

Fatty and Fried Foods: High-fat foods can slow digestion and trigger symptoms, particularly in those with IBS-D (diarrhea). Fried chicken, french fries, and rich creamy sauces are common irritants.
Caffeine: A stimulant, caffeine (found in coffee, tea, and some sodas) can speed up bowel activity, potentially causing diarrhea.
Alcohol: Alcohol can irritate the gut lining and affect motility, making it a common trigger for many people with IBS. Beer often contains gluten and other FODMAPs.
Spicy Foods: Hot and spicy dishes can stimulate the digestive system and cause irritation for some individuals.
Processed Foods: Many packaged snacks, ready meals, and fast food items contain hidden FODMAPs, high levels of sugar, and unhealthy fats that can worsen symptoms.

Avoiding foods based on IBS subtype

IBS manifests differently in individuals, with some experiencing primarily constipation (IBS-C) and others diarrhea (IBS-D). Some foods are better to avoid depending on your predominant symptoms.

Foods to avoid for IBS-C

Excess Insoluble Fiber: While some fiber is essential, too much insoluble fiber (found in fruit skins, whole grains like wheat bran) can worsen constipation for some. Soluble fiber from sources like oats and carrots is generally better tolerated.
Excessive Protein: Diets that are very high in protein can sometimes contribute to constipation.

Foods to avoid for IBS-D

Fatty and Fried Foods: As mentioned, these can exacerbate diarrhea by affecting the digestive speed.
Excess Fructose: Large amounts of fructose from high-fructose corn syrup or certain fruits can lead to diarrhea.
Caffeine and Alcohol: The stimulating effects of these can increase the frequency of bowel movements.

Comparing high-FODMAP foods and healthier alternatives

To help with meal planning, here is a comparison of common high-FODMAP triggers and some of their low-FODMAP alternatives that are generally well-tolerated.


High-FODMAP/Trigger Food	Potential IBS Reaction	Healthier Low-FODMAP Alternative
Onions & Garlic	Bloating, gas, cramping	Chives, scallion greens, garlic-infused oil
Apples & Pears	Bloating, gas, diarrhea (fructose)	Bananas (firm), blueberries, strawberries
Wheat-based Bread	Bloating, gas (fructans)	Gluten-free grains like rice, oats, quinoa
Cow's Milk & Ice Cream	Bloating, gas, diarrhea (lactose)	Lactose-free milk, almond milk, hard cheeses
Legumes (Lentils, Beans)	Gas, bloating (GOS)	Canned lentils (rinsed), small servings of canned chickpeas
Cauliflower & Broccoli	Bloating, gas (fructans, fiber)	Carrots, cucumber, eggplant, green beans
Artificial Sweeteners	Diarrhea, bloating (polyols)	Stevia, maple syrup (in moderation)

Conclusion: Personalizing your IBS diet

Discovering what foods should I avoid IBS can be a journey of trial and error, as triggers are highly individual. The low FODMAP diet provides a structured framework for identifying sensitivities by temporarily eliminating and then reintroducing certain carbohydrates. For many, common irritants like fried foods, caffeine, alcohol, and processed items are also significant triggers. The most effective strategy is to keep a food diary to track symptoms and identify your personal culprits. Working with a registered dietitian or gastroenterologist is highly recommended to ensure you maintain a balanced, nutritious diet while managing your symptoms effectively. The ultimate goal is to find a personalized eating pattern that minimizes discomfort and enhances your overall quality of life.

For more information and resources on the low FODMAP diet, consider exploring the materials provided by Monash University, the institution that developed the protocol.

Frequently Asked Questions

The low FODMAP diet is an elimination diet designed to manage Irritable Bowel Syndrome (IBS) symptoms. It involves temporarily cutting out foods high in fermentable carbohydrates (FODMAPs) that can cause gas and bloating, then reintroducing them to identify specific triggers.

Some people with IBS find that a gluten-free diet improves their symptoms. However, studies show that in many cases, it is the fructans (a type of FODMAP) found in wheat, barley, and rye—not the gluten itself—that are the trigger. A low FODMAP approach is often more effective.

Not necessarily. While many people with IBS are lactose intolerant and benefit from reducing dairy, some can tolerate lactose-free products or naturally low-lactose cheeses like cheddar and feta. Experimenting with smaller amounts and lactose-free options can help determine your tolerance.

High-fat foods can slow down digestion, which can worsen bloating and discomfort. In some individuals, particularly those with IBS-D, fatty meals can trigger diarrhea. Choosing lean proteins and healthier cooking methods like grilling or steaming is often recommended.

Caffeine is a stimulant that can increase bowel activity and may trigger diarrhea in some people with IBS-D. The effect is individual, so some may tolerate it in moderation, while others need to avoid it completely.

No, vegetables are an important part of a healthy diet. However, certain vegetables are high in FODMAPs (e.g., onions, garlic, broccoli, cauliflower) and can cause gas and bloating. Low-FODMAP vegetables like carrots, spinach, and eggplant are often well-tolerated alternatives.

It is best to start an elimination diet under the guidance of a healthcare provider or a registered dietitian. This professional can help you structure the phases of elimination and reintroduction safely, ensuring you receive adequate nutrition and accurately identify your trigger foods.