What to Eat When You Have Irritable Bowel Syndrome

FInd out “What to Eat When You Have Irritable Bowel Syndrome?” Identifying and avoiding the foods that aggravate irritable bowel syndrome (IBS) symptoms is one of the most difficult elements of having IBS.

There is no one diet that works for everyone because no two people are alike. For instance, those with IBS-D (IBS with diarrhea) may not experience the same triggers as those with IBS with constipation (IBD-C).

Having said that, there are a number of dietary strategies that seem to help the various IBS subtypes. With a little perseverance and some trial and error, you’ll ultimately find the food plan that can help keep your IBS symptoms under control. Some may need customizing to provide continuous comfort.

What to Eat When You Have Irritable Bowel Syndrome? Benefits

Irritable bowel syndrome is a medical condition characterized by abdominal pain and changes in bowel movement that, unlike inflammatory bowel disease (IBD), does not involve intestinal damage. In addition to IBS-C and IBS-D, there is also mixed-type IBS (IBS-M) in which diarrhea and constipation alternate.

In the same way that the cause of IBS is unclear, there has been limited clinical research to evaluate the effectiveness of various diets in treating the disease. What scientists do know is that specific foods and dietary practices are closely linked to the onset of IBS symptoms.1

Based on a review of the current research, the American College of Gastroenterology (ACG) issued dietary guidelines in 2014 to help people with IBS better manage the symptoms of IBS.2 Of the dozens of diets reviewed by the ACG, only two were found to be significantly effective in treating IBS symptoms: the low-FODMAP diet and the gluten-free diet.

In 2021 guidelines, the ACG stated, “Sensitivity to gluten is one of the most commonly reported reactions to food by patients with IBS.” The guidelines also recommended a limited trial of the low-FODMAP diet to improve overall IBS symptoms.3

Even so, there is little evidence that the diets will benefit all people with IBS or address the underlying causes that give rise to the disease, including gut motility disorders, pain hypersensitivity, and small intestine bacterial overgrowth (SIBO).

More often than not, an individualized approach will be needed to tailor an effective and sustainable diet plan, ideally under the supervision of a gastroenterologist. This may involve an elimination diet, in which suspected food triggers are removed from the diet and gradually reintroduced to see which, if any, cause IBS symptoms.

How It Works

Because IBS is such a complex disease, there is not one set route to take when designing the ideal diet plan. Most clinicians recommend a two-stage approach:1

1. Standard first-line recommendations include adhering to a regular meal pattern while reducing the consumption of insoluble fiber, alcohol, caffeine, spicy foods, and fat. Regular exercise and the avoidance of dehydration are also needed.
2. If these interventions fail to provide relief, then secondary measures—namely the implementation of a low-FODMAP or gluten-free diet—should be explored under the guidance of a qualified healthcare professional.

Additional tinkering may be needed if improvements are lacking or inconsistent. This would generally involve the identification of food triggers—including those that cause allergy or food intolerance—so that they can be avoided. The advice of a dietitian or nutritionist may also be needed to ensure you meet your daily nutritional goals.

Low-FODMAP Diet

FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are the short-chain carbohydrates found in many foods that tend to ferment and increase to the volume of liquid and gas in the small and large intestine.

The excessive consumption of FODMAPs can lead to the development of flatulence, bloating, and abdominal pain.4 Given that these are hallmarks of IBS, it makes sense that eliminating high-FODMAP foods would help prevent and/or ease these symptoms. The diet can be challenging, as many common foods are high in FODMAPs.

There are five types of FODMAPs:

• 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)

A low-FODMAP diet is designed in two phases as part of an elimination diet:5

• 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 AGC 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.3

Gluten-Free Diet

Many people with IBS will report an improvement in symptoms when they eliminate gluten from their diet, even if they do not have celiac disease.6 Gluten is a protein found in foods that contain cereals grains such as wheat, rye, and barley.

The notion that gluten plays a role in IBS is subject to debate. On the one hand, there are scientists who contend that IBS is a form of non-celiac gluten sensitivity, a poorly understood disorder similar to celiac in which gluten triggers adverse gastrointestinal symptoms.7 Others argue that the FODMAP fructan, rather than gluten, is the problem.8

If a low-FODMAP diet is unable to provide relief, a gluten-free diet may be attempted to see if your symptoms improve. If they do, gluten intake may be increased to see how much of the protein you can reasonably tolerate. Doing so may allow you to eat a wider range of foods without such strict dietary controls.

A gluten-free diet is defined as having less than 20 parts per million (ppm) of gluten per day. A low-gluten diet generally involves less than 100 ppm of gluten.

Before starting a gluten-free diet, it is important to test for celiac disease by serological testing, Transglutaminase IgA antibody and total IgA levels. If patients have low IgA levels (approx 2-3% of the population) then the Deamidated gliadin peptide IgG antibody is used for screening. If the serological tests are equivocal, then genetic testing is the next step.

Duration

Whichever dietary approach you take, adherence is key. Unlike some eating plans, IBS diets are generally intended for a lifetime and often require you to make significant lifestyle changes. This may not only include the avoidance of alcohol, caffeine, and fatty foods, but also the regular use of exercise to normalize bowel function and lose weight. A diet alone can often fall short in controlling IBS symptoms if you remain inactive and/or overweight.9

At present, there is no indication that a low-FODMAP diet or gluten-free diet can be used on an “as-needed” basis to treat acute symptoms. With that said, you may want to increase your intake of certain foods if you have diarrhea or eat extra prunes or bran on days when constipation symptoms are acute.

What to Eat 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.10

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

What to Eat 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.

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.1

Recommended 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. Doing so ensures that the bowels move regularly and gently, as opposed to suddenly being full and then having nothing in them for five to six hours straight.

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 (referred to as a gastrocolic reflex). Doing so may keep you regular throughout the day. Taking a short walk after eating also helps, as can sitting in a chair during meals rather than slouching on the sofa.

The same applies to eating on the run, 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.

Cooking Tips

When embarking on an IBS diet, the number-one rule is to avoid any deep-fat frying. As much as you may enjoy French fries, donuts, or fried chicken, these types of foods are banned whether you have IBS-C or IBS-D.

Instead, grill, roast, or pan-fry meats with as little oil as possible. One trick is to spray oil onto the meat rather than pouring oil into the frying pan. You can also lightly sear meat, chicken, or fish to get a nice crust and then finish it off in a hot 425-degree oven for a few minutes just like restaurants do. An air fryer may also be a good investment.

Vegetables

Steaming vegetables make them more digestible, especially if you are prone to diarrhea. If you love salads but find them hard to digest, look for cooked salad recipes (like a Mediterranean Heart of Palm Salad or a Grilled Eggplant Salad). Peeling vegetables, tomatoes, and fruit also makes them more digestible.

Instead of salad dressings or sauces, use a squeeze of lemon or lime, some chopped fresh herbs, or a mild tomato or mango salsa to flavor foods.

Beans

To reduce gassiness from canned beans, rinse them thoroughly and allow them to soak in a bowl of cold water for 30 minutes. If starting from scratch, soak the dried beans twice—first in hot water for a couple of hours, then in cold water overnight—before cooking them slowly in fresh water until very soft.

Some people claim that adding ground ajwain (a type of caraway) or epazote (a Mexican herb with a pine-like aroma) can dramatically reduce the gassiness of beans as they cook. While there’s no proof of this, it can’t hurt to try it.

Modifications

The low-FODMAP and gluten-free diet are both considered safe in adults as long as the daily recommended intake (DRI) of protein, carbohydrates, and nutrients are met. With that being said, nutritional deficiencies are common due to the diets’ lack of whole grains, dairy, and other important food groups.

These concerns are amplified during pregnancy, when nutritional demands are increased. A gluten-free diet, for example, is typically low in:

• 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, these shortcomings demonstrate how detrimental these diets can be if left unsupervised.

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

All diets should be supervised by a healthcare provider or certified dietitian, and dietary supplementation is typically recommended to help bolster nutrition.

Considerations

Diets as restrictive as the low-FODMAP and gluten-free diet can be difficult to sustain. They require a commitment on your part as well as buy-in from your family. By focusing on the benefits to your health and well-being rather than the foods you’re deprived of, you can learn to cope with the challenges of the diet and begin to normalize IBS in your life.

General Health

Both the low-FODMAP and gluten-free diets have their benefits and shortcomings. For the most part, the diets can be used safely in people with diabetes and hypertension (high blood pressure) since many of the foods are considered beneficial to these conditions.

Both diets require a period of adjustment during which time you may experience short-term side effects likes tiredness or bloating. Most of these resolve over time, although some (like food cravings) take concerted effort to control.

The greater concern is the long-term impact of the diets on your health. Beyond the aforementioned risk of nutritional deficiencies, some scientists are concerned that restrictive diets like these (particularly those used without medical motivation) can lead to disordered eating.11 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.

Others question whether the long-term use of restrictive diets might permanently alter the gut flora, increasing the risk of bowel infection.11 There is even evidence that certain food restrictions can affect heart health.

Sustainability and Practicality in the Real-World

One of the common drawbacks to the low-FODMAP and gluten-free diets is the impact they have on one’s social life. A 2018 review of studies in Gastroenterology & Hepatology reported that the persistent dedication to a restricted diet contributes to increased rates of social isolation as well as feelings of anxiety and inadequacy if adherence to the diet falls short.13 Luckily, there are ways around some of these concerns.

Dining Out

Unlike previous decades, gluten-free dining options have increased considerably, making it easier to dine out with friends, families, and work associates. Some casual dining chains have even gotten in on the act.

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.

Food Preparation

Home-cooking has obvious health advantages but is especially valuable if you have IBS, as it provides you full control over your ingredients. The advent of the low-FODMAP and gluten-fee 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.

Cost

Another issue is the typically higher cost of gluten-free and low-FODMAP foods at grocery stores.

A 2018 study from the United Kingdom reported that gluten-free foods were 159% more expensive than their regular counterparts.14 This can make the cost of gluten-free eating prohibitive (although the costs can usually be reduced by avoiding packaged foods and eating real foods prepared at home).

By contrast, low-FODMAP packaged foods are relatively difficult to find, with only a handful of specialty producers (Rachel Pauls Food and Fody) offering snacks, spices, dressings, and soup bases. These also tend to be quite costly.

Side Effects

Both low-FODMAP and gluten-free diets have side effects, many of which will resolve on their own as your body adapts to the eating plan

As profound as some of these symptoms can be, most people who turn to an IBS diet because of severe symptoms find them to be reasonable trade-offs in the long run.

Support and Community

It is hard to go it alone if you decide to start an IBS diet. As much as may want to avoid “burdening” your family with your decision, you may find it harder to cope if you isolate them from what you are going through.

Instead, make them a part of the process by educating them about what IBS is and how the diet is meant to help. In some cases, it may open the door to making positive changes to your entire family’s diet, rather than ones that only benefit you. Looping them in also means you are more likely to gain their support and less likely to be sabotaged by those who might dismiss the diet as a “fad.”

If you are struggling to cope with the diet, let your healthcare provider know so that adjustments can be made. You should also seek support from others who have experienced what you are going through.

There are plenty of IBS support groups on Facebook as well as community forums offered by the non-profit IBS Patient Support Group. Your healthcare provider may also know about live IBS support groups in your area.

There are even low-FODMAP apps and gluten-free apps that can help keep you on track if you need support, encouragement, or inspiration.

Low-FODMAP Diet vs. Elemental Diet

Small intestinal bacterial overgrowth (SIBO) is a condition where excessive gut bacteria are present in the small intestine. It is one of the more common contributing factors for IBS and one that is often treated with a low-FODMAP diet.

However, in recent years, a disease-specific elemental diet was established with the aim of hindering bacterial growth and restoring the normal gut flora in people with SIBO.

This liquid diet is controversial given that it involves the prolonged use of fluids consisting primarily of amino acids, sugars, vitamins, and minerals. It typically lacks protein (or contains only small amounts of protein) due to the risk of hypersensitivity in some people. Fat is usually limited to 1% of the total calories.

Benefits and Challenges

There is some evidence that the elemental diet can help people being treated for SIBO with antibiotics. The diet works by delivering nutrients to the first part of the small intestine. By the time the liquid reaches the lower bowel, there are few nutrients left to “feed” the gut bacteria. This mechanism of action may help resolve bacterial overgrowth.

An early study in Digestive Diseases and Science reported that the elemental diet helped normalize IBS symptoms in 74 of 93 adults after 14 days, increasing to 79 adults by day 21.15 Other studies have not reported such positive findings.

The biggest challenges of the elemental diet are, firstly, adherence and, secondly, the prolonged restriction of protein and fat. Depriving yourself of protein and fat for this amount of time can lead to a profound array of symptoms and complications, including fatigue, muscle weakness, loss of lean muscle mass, irregular heartbeat, infection, and more.

A Word From Verywell

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.