Cooking Without Onions and Garlic for IBS

If you have irritable bowel syndrome (IBS) or another gastrointestinal disorder, you may need to cook with onion and garlic substitutes or alternatives. This is because garlic and onions are high in fructan, which is hard for your small intestine to absorb. When fructan is fermented by gut bacteria in the large intestine it can cause IBS symptoms.

Fortunately, there are onion and garlic substitutes you can use when cooking for a low-FODMAP diet. This article looks at some of those substitutes, how to use them, and why you should avoid garlic and onions if you have IBS.

A man chopping garlic and onions
Marshall Gordon / Cole Group / Photodisc / Getty Images

Why Is Garlic Bad for IBS?

Garlic and onions are very high in fructan, which is a type of carbohydrate called an oligosaccharide. Humans don't have the enzymes to digest many oligosaccharides, including onions and garlic, so they aren't absorbed by the small intestine. Instead, they travel to the colon where they feed the good bacteria in the gut.

People with IBS or other gastrointestinal issues are more sensitive to this process. For them, it can cause a buildup of gas, water, or both that can lead to pain, bloating, flatulence, or diarrhea.

What Other Foods Should You Avoid With IBS?

In addition to garlic and onions, other foods you may want to avoid if you have IBS include:

  • Fruits such as apples and cherries
  • Milk
  • Wheat products
  • Veggies such as cauliflower, beans, and asparagus
  • Sweeteners
  • Honey

Using Garlic and Onions When Cooking

Garlic and onions are often used in cooking as aromatics—foods that add a savory aroma and flavor to other dishes. They are found in cuisines around the world, making it difficult to avoid them by sticking to foods from a certain geographical area.

Often, garlic and onions are added at the very beginning of cooking to mellow their flavors before building a sauce, soup, or other complex dishes.

How to Replace Garlic and Onions When Cooking

Can you just leave the garlic and onions out of a recipe? Sometimes. You'll usually get acceptable results—it's not the same as leaving eggs out of a cake. However, most people would find some recipes unacceptably bland.

Consider adapting the recipe with a substitute rather than simply dropping onions or garlic if:

  • Onions or garlic are the only flavorings in the recipe.
  • Onions or garlic are a major part of the recipe.
  • Onions or garlic are used raw or lightly cooked.

In these situations, the flavor of onion or garlic may be critical to a delicious dish. Most of the time, though, you can find a good substitute.

What Are Aromatics?

Aromatics are foods that release strong flavors and aromas when cooked. They are added at the beginning of the dish and combined with oil or butter to form the dish's base.

What Are Good Garlic Substitutes?

No unrelated vegetable has quite the same taste as garlic, but some aromatics that may be good options for cooking include:

  • Fennel, which has a licorice-like taste but onion-like texture. Try it with chicken or fish.
  • Celery, among the most common aromatics.
  • Bell peppers, a vegetable that's often used in Cajun cooking. Green peppers and celery are a good base for rice dishes or savory stews.
  • Carrots, often used as an aromatic in French cooking in combination with celery.
  • Celeriac, or celery root, which is the knobby root of one variety of celery. Peeled and diced, it can be used as an aromatic in sauces or stews.

While most onions are high in FODMAPs, chives or the green part of spring onions are not and can be used as replacements for regular onion.

Substitute Herbs and Spices

Garlic chives, an herb with a garlicky flavor, are an obvious substitute, but here are other herbs and spices you may find useful:

  • Peppercorns—white, pink, or Szechuan—can add different flavors to your cooking.
  • Cumin's distinctive taste may work well in some recipes, especially where garlic is used raw.
  • Horseradish, freshly grated, can add some of the pungent notes you might otherwise lack.
  • Ginger and galangal have distinctive flavors but may be useful in stir-fries as aromatics.
  • Asafoetida is a spice from India with a very strong smell that, when added to warm oil, tastes much like garlic and onions. You need only a sprinkle, as it's very strongly flavored.

Garlic or Onion Powders and Salts

Garlic powder and garlic salt are made from dehydrated, finely ground garlic. Onion powder and salt, likewise, are made from onions.

Usually, garlic powder and onion powder can be used to give food flavor without irritating your stomach. Ask your healthcare provider before trying another form of a food that has caused painful symptoms in the past.

Infused Oil

Those avoiding garlic and onions due to FODMAPs can use garlic-infused oil as the fructans are not fat-soluble. You can buy infused oil or saute onions and garlic in oil and discard the solids before using it in your dish.

Note that making your own infused oil and storing it has a risk of botulism, so use it immediately; otherwise, you may want to buy commercially prepared infused oil for safety. 

What Is a Low-FODMAP Diet?

FODMAPs are a group of carbohydrates in common foods believed to contribute to IBS symptoms. Like fermentable oligosaccharides, other types of carbs that make up the FODMAP acronym—disaccharides, monosaccharides, and polyols—are also not fully absorbed in the small intestine and can cause symptoms such as bloating and pain for people who are sensitive to them.

People who follow a low-FODMAP diet eliminate all FODMAP foods for a period to relieve symptoms. Then they slowly reintroduce each FODMAP food back into their diet so they can determine which food is contributing to their symptoms.


If garlic or onions contribute to IBS symptoms or you are following a FODMAP diet to determine if they do, you will likely want to cut these alliums from your diet. Fortunately, there are a number of substitutes that can give the same effect, from other aromatics such as fennel and bell peppers to herbs and spices like ginger and horseradish. Oil infused with garlic and garlic powder are also possible substitutes.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. International Foundation for Gastrointestinal Disorders. The low FODMAP diet approach.

  2. American Chemical Society. Fermentable foods: Trouble in your diet.

  3. Iacovou M, Tan V, Muir JG, Gibson PR. The low FODMAP diet and its application in East and Southeast Asia. J Neurogastroenterol Motil. 2015;21(4):459-470. doi:10.5056/jnm15111

  4. U.S. Department of Agriculture. Can you get botulism from garlic oil?

By Victoria Groce
Victoria Groce is a medical writer living with celiac disease who specializes in writing about dietary management of food allergies.