Foods to Eat and Foods to Avoid on an IBS Diet

An IBS diet generally includes low FODMAP foods, like potatoes, oats, or carrots, and foods with less insoluble fiber. Proper hydration is also important. Foods to avoid can include alcohol, caffeine, and spicy or fatty foods. Recommendations can vary, however, depending on the type of irritable bowel syndrome.

People who have IBS with diarrhea (IBS-D) may not have the same triggers as those who have IBS with constipation (IBS-C). People who experience symptoms of both IBS-C and IBS-D (mixed type IBS or IBS-M) may have a combination of triggers. Even within each subtype, identifying and avoiding the foods that set off IBS symptoms will be different for everyone.

Low-FODMAP Diet for IBS

FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are short-chain carbohydrates found in many foods. They tend to ferment and increase the volume of liquid and gas in the small and large intestines.

Excessive consumption of FODMAPs can lead to flatulence, bloating, and abdominal pain. Given that these are hallmarks of IBS, it makes sense that eliminating high-FODMAP foods would help prevent or ease these symptoms.

Foods to Avoid

This diet can be challenging, as many common foods are high in FODMAPs.

There are five types of FODMAPs to avoid:

• Fructans (found in wheat, onions, garlic, barley, cabbage, and broccoli)
• Fructose (found in fruit, honey, and high-fructose corn syrup)
• Galactooligosaccharides (found in legumes and beans)
• Lactose (found in milk and other dairy foods)
• Polyols (found in stone fruits, sweet potatoes, apples, and celery)

Foods to Consume

Foods that are low in FODMAPs and can be consumed on a low FODMAP diet include:

• Eggs
• Meat
• Tempeh and firm tofu
• Some grains such as rice, oats, quinoa, and spelt
• Non-dairy milk alternatives, like almond milk
• Some cheeses (brie, Camembert, cheddar, feta, and hard cheeses)
• Some types of fruit (grapes, oranges, strawberries, blueberries, and pineapple)
• Some vegetables (eggplant, potatoes, tomatoes, cucumber,s and zucchini)
• Some types of nuts, such as Macadamia nuts, peanuts, pumpkin seeds, and walnuts

Timing Your Low FODMAP Diet

A low-FODMAP diet is designed in two phases as part of an elimination diet:

• Phase 1: Foods high in FODMAPs are restricted for a short period of time, generally between three to six weeks.
• Phase 2: The foods are reintroduced into the diet, one FODMAP type at a time, to assess your tolerance to each.

The American College of Gastroenterology (ACG) recommends this be done under the guidance of a properly trained gastrointestinal nutritionist. If that's not possible, they urge healthcare providers to give you high-quality materials to help guide you through it in a medically responsible way.

Gluten-Free Diet for IBS

If a low-FODMAP diet is unable to provide relief, a gluten-free diet may be attempted to see if your symptoms improve. Gluten is a protein found in foods that contain cereal grains such as wheat, rye, and barley.

Many people with IBS report an improvement in symptoms when they eliminate gluten from their diet. However, there is significant disagreement in the scientific community about whether or not gluten plays a role in irritable bowel syndrome.

Foods to Consume

Many foods do not naturally contain gluten. But it is always important to look for a gluten-free label on prepared or processed food packages because some foods are exposed to gluten during the manufacturing process.

These foods are generally safe to consume on a gluten-free diet:

• Gluten-free grains such as quinoa or rice
• Oats (only those that have a gluten-free label)
• Fresh fruit
• Vegetables
• Fresh meat and poultry
• Fish and seafood (unless breaded or processed)
• Most dairy products without additives
• Beans and legumes
• Nuts and seeds
• Wine
  

Foods to Avoid

Gluten may be hiding in foods that you may not expect. You should avoid the following foods on a gluten-free diet:

• Foods made with wheat, rye, barley, or oats
• Processed meats
• Creamed vegetables
• Dairy products made with fillers or additives, including many types of yogurt or ice cream
• Processed cheese or foods that come with cheese mixes
• Flavored coffee drinks or malted milk, or tea made with malted barley.
• Some forms of dairy, such as low-fat or fat-free cottage cheese, or sour cream
• Processed soups (like canned soup or dry soup mixes)
• Certain types of alcohol made from grains, such as beer, gin, and whiskey
• Foods made with modified food starch, food starch, hydrolyzed vegetable protein, stabilizers, or fat replacers or substitutes.
  

Fiber-Rich Diet for IBS-C

To ease chronic IBS-associated constipation, you will almost inevitably need to eat more fiber. It is important to increase the intake gradually to allow your body time to adjust. Generally speaking, soluble fiber is better tolerated by people with IBS than insoluble fiber.

You will also need to eat foods that contain healthier fats (polyunsaturated or monounsaturated fat). Foods that are high in saturated fat and sugar are known to promote constipation.

Bland Diet for IBS-D

If your IBS symptoms involve diarrhea, it is best to stick with bland foods, especially if your symptoms are severe. Fatty, greasy, or creamy foods are to be avoided as they can speed up intestinal contractions, causing cramping and runny stools. Fatty foods should also be avoided if you have IBS-M.

Avoid insoluble fiber, which draws water from the intestine, making stools loose or watery. Though you should make every effort to eat fruits and vegetables, it is best to limit your intake of fiber to less than 1.5 grams per half-cup during acute episodes.

More Tips and Recommendations

Once you find the right diet for you, it's important to stick with it. Unlike some eating plans, IBS diets are generally intended for a lifetime and often require significant lifestyle changes, like regular exercise. A diet alone can often fall short in controlling IBS symptoms if you remain inactive and/or overweight.

Consider some of these tips to help manage irritable bowel syndrome:

• Vary your meal timing: Many people with IBS find that eating smaller, more frequent meals places less stress on the digestive tract than sitting down for three large meals. However, some people with IBS-D may be advised to eat a substantial breakfast or sip coffee first thing in the morning to stimulate a bowel movement.
• Slow down at meals: How you eat plays a role in whether you experience IBS symptoms or not. Eating slowly with concerted pauses between bites can reduce the amount of air you swallow during a meal. Also, avoid sipping drinks through a straw and chewing gum, each of which introduces air into the stomach and increases the risk of gas, bloating, and stomach pain.
• Experiment with cooking methods: Avoid frying foods and try grilling or roasting instead. Try steaming or boiling veggies. An air fryer may also be a good investment.
• Prep foods with digestibility in mind: Peeling vegetables, tomatoes, and fruit also makes them more digestible. To reduce gassiness from canned beans, rinse them thoroughly and allow them to soak in a bowl of cold water for 30 minutes.
• Dine out with caution: Even if a restaurant isn't gluten-free or doesn't have low-FODMAP options, you can check the online menu before you arrive and usually find something you can eat. Some restaurants may even make accommodations if you call far enough in advance and advise them of your dietary concerns.
• Investigate available resources: The advent of low-FODMAP and gluten-free cooking has inspired food bloggers to post their favorite recipes online, many of which are good for the family as well as friends. For those who are too busy to cook, there is a growing number of meal kit delivery services that specialize in gluten-free foods as well as several that have started to offer low-FODMAP options.

Special Considerations

Gluten-free and low FODMAP diets are considered safe in adults as long as the daily recommended intake (DRI) of protein, carbohydrates, and nutrients is met. With that being said, nutritional deficiencies can occur due to the diets' lack of whole grains, dairy, and other important food groups.

There are some groups that should take extra care when following any restrictive diet.

Pregnant People

Nutritional demands increase during pregnancy, and following these diets may not meet your dietary needs. Both low-FODMAPs and gluten-free diets eliminate wheat and may be low in nutrients common in wheat-containing foods, such as:

• Iron
• Folate
• Fiber
• Calcium
• Thiamine
• Riboflavin
• Niacin

All of those nutrients are necessary for normal fetal development. While prenatal vitamins can help overcome these deficiencies, it is important to work with your healthcare provider when changing your diet during pregnancy to ensure that you get adequate nutrition.

Children

Nutrient deficiencies are one of the reasons why low-FODMAP and gluten-free diets are used with caution in children who otherwise need a healthy, balanced diet to ensure normal growth and development.

In children, a low-FODMAP diet is only used when recommended by the child's doctor. Similarly, a gluten-free diet should only be used in children who are positively diagnosed with celiac disease or non-celiac gluten intolerance.

Risk of Eating Disorders

Some scientists are concerned that restrictive diets like these (particularly those used without medical motivation) can lead to disordered eating. This was evidenced in part by a 2017 study from Sweden in which young girls with celiac disease were 4.5 times more likely to have anorexia than those without.

Summary

The relationship between food and IBS is a complex one, but there are changes you can make in both how you approach meals and the foods you choose to eat.

A smart eating strategy can dovetail nicely with the medical treatment you receive from your healthcare provider to relieve and control IBS symptoms.