When it comes to irritable bowel syndrome (IBS), identifying which foods create negative symptoms and which foods are safe to eat can make a world of difference.
Managing these symptoms with effective dietary changes as well as implementing supplements to boost gut health are effective ways to keep flare-ups at bay.
At the bottom of this page we make specific recommendations for prebiotics, probiotics, and digestive enzymes. First let’s learn more about the foods you should avoid — and include — in your diet.
Foods to Avoid
Foods that aggravate IBS symptoms will vary from person to person and may depend upon which IBS subtype is present such as:
- Constipation-predominant (IBS-C)
- Diarrhea-predominant (IBS-D)
- Predominant irregular (mixed diarrhea/constipation) (IBS-M)
- Unclassified (IBS-U)
Keeping a food journal can help to identify foods that trigger IBS symptoms.
These symptoms can come on in the form of abdominal pain, cramping, gas, or bloating. However, there are times when it can be challenging to pinpoint a trigger food — there are other variables that can cause digestive symptoms such as stress or infection. Also, food reactions don’t always occur in the same timeframe in each instance.
Known trigger foods for IBS include:
Lactose-containing dairy is a culprit in many adults because their bodies do not produce enough lactase, the enzyme which is responsible for breaking down the lactose in milk. Some ethnicities produce a higher amount of lactase than others.
When the body does not produce enough lactase to break down the lactose, it can cause gas, bloating, pain, nausea, and/or diarrhea. Softer dairy products such as cream cheese, ice cream, and cottage cheese are higher in lactose and more likely to cause symptoms.
If you need to avoid or minimize lactose, here are your options:
- Try consuming lactose-free milk
- Substitute dairy for plant or nut-based milks instead
- Dairy foods that contain lower amounts of lactose include hard/aged cheeses (parmesan, cheddar and Swiss cheese), butter, whey protein isolate, and heavy cream
- Researchers believe that people with lactose intolerance can consume up to 12g of lactose in one meal without experiencing side effects
- Lactose consumed in yogurt is better tolerated than the same amount in milk
Unfortunately, fruit can be a trigger food because most fruits are either high in fructose or have a high fructose to glucose ratio. People who experience IBS symptoms from fruit are known to have “fructose malabsorption” — a genetic component that may be triggered by conditions such as SIBO (Small Intestinal Bacterial Overgrowth).
Fruits that are lower in fructose or have an ideal fructose to glucose ratio include:
- Fresh figs
Cruciferous vegetables are harder to digest because they contain an oligosaccharide called raffinose. Humans are unable to produce an enzyme that can break down this compound, which makes it so hard to digest. Cruciferous vegetables also contain sulfur, which converts into hydrogen sulfide, which can cause diarrhea in those with a high level of bacteria that produce this compound.
This is what causes gas as well as gas that smells like rotten eggs. Examples of cruciferous vegetables are:
- Brussels sprouts
Beans and Legumes
These contain compounds called galacto-oligosaccharides, which are undigestible and therefore available for bacterial fermentation. Consuming the following foods can cause gas and bloating:
- Split peas
- Black-eyed peas
Canned lentils are usually the best tolerated of the legumes for those who are sensitive. Up to 1/2 cup in one meal is considered a safe dose, but it may be best to start with 1-2 tablespoons initially.
Sugar substitutes such as polyols (e.g., xylitol, sorbitol, maltitol) cause diarrhea and bloating so are best avoided. (Mäkinen, 2016)
Other alternative sweeteners such as aspartame and sucralose may cause a gastrointestinal issue. Research in rats demonstrates a reduction in beneficial gut bacteria.(Schiffman & Rother, 2013)
Other foods you may want to avoid include caffeine, fatty foods, and alcohol.
Diets and Foods to Have
While avoiding trigger foods is important, IBS patients may experience a higher level of relief by following a particular diet plan that targeting specific issues related to their IBS subtype. Some successful diet choices to choose from are:
FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are all carbohydrates that are particularly hard to digest in those with IBS.
FODMAP foods include a variety of grains, fruits, artificial sweeteners, dairy products, and vegetables. Limiting high-FODMAP foods can significantly improve IBS symptoms. Some great low-FODMAP foods are:
- Alfalfa and bean sprouts
Lactose-free dairy, plant-based milks, and hard cheeses
- Almond milk*
- Cashew milk*
- Hemp milk
- Coconut milk
- Rice milk
- Feta cheese
- Parmesan, cheddar, Swiss cheese
*Best limited to no more than 1/2 cup per sitting
- Corn flour
- Sourdough spelt bread
Nuts and seeds
- Pine nuts
- Pumpkin seeds
*Limited to one handful per sitting
A gluten-free diet has the potential to reduce IBS symptoms. This is because gluten can cause intestinal damage in those who have a gluten sensitivity or intolerance. Luckily, finding gluten-free bread and pasta is relatively easy. Types of gluten-containing grains and the products to avoid include:
Eliminate possible trigger foods until IBS symptoms dissipate. Keep a food diary for two weeks and identify suspected culprits. Remove these from your diet for four weeks — or until symptoms improve significantly. Then reintroduce one at a time.
- Choose one food to reintroduce first, and have three servings of it across the day. Monitor for reactions. If there is a reaction, then that food needs to be removed. If for the next two days there is no reaction, then that food is considered “safe.”
- Return to the elimination diet and wait another two days before reintroducing another food.
- Typically the diet lasts up to 8 weeks, depending on how many foods need to be removed and reintroduced.
Common trigger foods to stay away from are:
- Insoluble fiber
- High-fat foods
- Spicy foods
If the elimination diet in this form doesn’t help, consider the Low FODMAP diet or seek out a trained practitioner for individual guidance.
Those with IBS can be easily triggered by foods which are high in fat and low in fiber. Fatty foods are especially problematic for people with IBS-M. By focusing on low-fat foods, flare-ups are likely to stay at a minimum. When eating a low-fat diet, focus on eating:
- Lean meats and proteins
- Low-fat dairy
Along with managing your diet, certain supplements can help give your gut the boost it needs to repair any damage it has accrued, as well as make your gut healthier and stronger. Supplements that can help those suffering from IBS include:
Taking prebiotic fiber is a great way to fight against IBS symptoms, including constipation. You can get it through consuming whole grains, fruits, vegetables, and beans. However, taking an over-the-counter soluble fiber supplement can help move things along a little faster if you are unable to get enough fiber from your diet.
Products we recommend include:
*Contains some lactose
Beneficial bacteria through probiotic supplementation is a great way to get rid of IBS symptoms such as abdominal pain, gas, and the overall severity of IBS. (Didari, Mozaffari, Nikfar, & Abdollahi, 2015)
You can also get probiotics through foods such as kimchi, sauerkraut, miso, kefir, and aged cheeses.
Products we recommend include:
Digestive enzymes help the body to break down the foods we eat. For people with IBS, the body may not have the enzymes it needs to break down fats, carbohydrates, and proteins.
By supplementing with a good digestive enzyme, it can improve digestion and give relief of symptoms caused by IBS. (Money, Walkowiak, Virgilio, & Talley, 2010)