Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder that affects around 15 percent of people in the United States. A functional gastrointestinal disorder is defined as one in which the GI tract doesn’t always work, but there are no discernible structural abnormalities. Similarly, when doctors administer tests, the results come back as usual.

In 2019, “The American Journal of Gastroenterology” described a study in which researchers found differences between the gut bacteria of patients with irritable bowel syndrome and people with healthy digestive tracts. Some genera of bacteria are more common in patients with IBS, and others are less common. The scientists speculated that differences in gut bacteria populations could affect a patient’s ability to digest certain foods.

Who Suffers from Irritable Bowel Syndrome?

Irritable Bowel Syndrome is twice as common in women as in men. Its symptoms can range from mild to severe, and they can include the following:

  • Alternating constipation or diarrhea or both
  • Pain in the abdomen
  • Altered bowel habits
  • Bloating and gas
  • Feeling of fullness

There are many ways to treat irritable bowel syndrome. These may include lifestyle changes, like getting regular exercise and managing stress. Modifying one’s diet is another treatment for IBS. This process can be tricky, for different patients react differently to different foods. For example, foods with a lot of fiber can ease constipation in some patients but cause stomach pain or bloating in others. An IBS patient should keep a diary for a few weeks to help them identify foods or other possible triggers that cause or exacerbate their symptoms.

Some doctors recommend a low FODMAP diet for IBS patients. The acronym is Fermentable, Oligo-, Di, Monosaccharides, and Polyols. They all describe carbohydrates that are known to cause or worsen irritable bowel syndrome symptoms. Some of the 20 foods listed below are high in FODMAPs.

irritable bowel syndrome
Here are seven signs you need a digestive system “reset.”

20 Foods That Can Worsen Irritable Bowel Syndrome Symptoms

1. Alcohol

Alcohol is not digested like other foods; the stomach absorbs only 20 percent of it, while the small intestine absorbs the rest. Thus, alcohol can throw the digestive system out of whack. As the alcohol passes through the stomach, it causes the stomach to produce abnormally high amounts of stomach acid. The stomach is so busy producing acid that it can’t ward off harmful bacteria; some travel down the digestive tract. Similarly, alcohol can damage the mucous cells in the stomach and cause inflammation and lesions in the stomach lining.

2. Dairy products can lead to irritable bowel syndrome

Lactose intolerance is the inability to digest the carbohydrates in milk fully. Babies are born with the ability to produce an enzyme called lactase that enables them to metabolize lactose. As they get older, they often lose the ability to produce lactase and thus become lactose intolerant. In 2017, “The Lancet: Gastroenterology and Hepatology” published an analysis of multiple studies that demonstrated that the incidence of lactose intolerance varied by country. The researchers found that while around 67 percent of adults worldwide are lactose intolerant, only 4 percent of the adults in Denmark are, while 100 percent of the adults in South Korea are lactose intolerant.

Dairy products like milk, cheese, and ice cream can cause constipation, diarrhea, bloating, and cramps in lactose-intolerant patients. A few kinds of cheese have relatively low levels of lactose; examples include Parmesan, Mozzarella, Camembert, and Brie. The bacteria in yogurt break down the lactose in it, making it another possible option. IBS patients may also try lactose-free dairy products.

3. Fruits with pits

Fruits with pits like peaches and cherries often contain a lot of fructose, a monosaccharide and thus one of the FODMAP carbohydrates. Fructose can affect patients with IBS the way that dairy products affect lactose intolerant people.

4. Other sources of fructose contribute to irritable bowel syndrome

Fruits with pits aren’t the only food items containing much fructose. Such items include the following:

•High-fructose corn syrup

Fortunately, there are fruits like bananas, oranges, and strawberries that are relatively low in fructose. Besides, some people have reported that eating fruit raw makes their symptoms worse. Conversely, cooking fruit may make it easier to digest.

sugar addiction

5. Red meat

While red meat is a good source of nutrients like Vitamin B12, it’s also hard to digest. Poultry and fish are generally easier to digest.

6. Chocolate

Chocolate contains a variety of ingredients that can cause IBS. It contains caffeine, which is a diuretic and can thus make stools dryer and harder to pass. Chocolate cakes and bars are made with milk, which can cause constipation. Foods made with chocolate are also loaded with sugar.

7. Artificial sweeteners

The science journal “Molecules,” however, described a study demonstrating how artificial sweeteners like sorbitol affect the digestive system. The researchers fed six types of artificial sweeteners to mice over four weeks. The mice suffered such gastrointestinal ills as diarrhea and indigestion. The researchers found that the artificial sweeteners were actually poisonous to the mice’s gut bacteria. The artificial sweeteners also impaired the mice’s ability to metabolize glucose.

8. Fried and fatty foods

Fried food is bad for digestion, especially if it is also high in fat. Fatty, fried foods like French fries, chips, and specific cuts of meat, contain a lot of saturated fat, which the human body has trouble digesting. Therefore, the body must produce more digestive enzymes and gastric acids than usual to digest them properly. Fried foods also disrupt the balance between the gut bacteria in the stomach. Since the body has to work extra hard to digest fried food, it can cause unpleasant symptoms like indigestion, diarrhea, and nausea.

9. Processed food

More commonly known as junk food, processed food is bad for IBS patients in many ways. It is often fatty, so it is hard to digest. It often contains artificial sweeteners and food additives. While the latter extend a food’s shelf life and make it look more appealing, many people have trouble metabolizing food additives.

irritable bowel syndrome

10. Wheat

Some people are sensitive or allergic to gluten, a substance found in wheat. Wheat also contains fructans, a type of carbohydrate related to fructose. Fructans are among the FODMAPs and are thus some of the carbohydrates that can trigger symptoms of irritable bowel syndrome, including diarrhea, bloating stomach pain, and constipation.

Unfortunately, wheat is also a good source of fiber. So people who need to avoid wheat will need to find other sources of fiber to keep their digestive tract working properly.

11. Rye may cause irritable bowel syndrome

Rye is another source of fructans. As such, it can trigger symptoms of irritable bowel syndrome.

12. Carbonated drinks

Carbonated drinks like Coca-Cola, ginger ales, and soda water can increase intestinal gas and cause bloating. Diet sodas are just as likely to cause gas as regular sodas, and they contain artificial sweeteners that can also cause problems. Regular sodas contain lots of sugar that can cause an imbalance in the gut bacteria, resulting in more gas.

13. Caffeinated drinks

Caffeine can cause diarrhea in some patients with irritable bowel syndrome and can worsen the dehydration caused by diarrhea. Examples of drinks that can contain caffeine include coffee, tea, and some sodas. Some over-the-counter medications like the headache remedy Excedrin can also contain caffeine.

14. Cruciferous vegetables

Cruciferous vegetables are leafy green vegetables like kale, cauliflower, and Brussels sprouts. Many contain a sugar called raffinose that humans can’t digest. Consequently, cruciferous vegetables are hard to digest and cause diarrhea and/or constipation.

15. Other vegetables high in FODMAPs

Some vegetables contain a lot of FODMAP carbohydrates. Examples include the following:


Like fruit, raw vegetables are more likely to trigger symptoms than cooked vegetables. Vegetable juice may also be easier on the system.

irritable bowel syndrome

16. Beans and legumes

Beans and legumes both contain carbohydrates that are hard for the body to digest properly. The gut bacteria ferment the undigested parts and thus cause intestinal gas. Examples of beans and legumes include the following:

•Baked beans
•Black-eyed peas
•Kidney beans
•Lima beans

Some patients can eat small amounts of canned chickpeas or lentils, providing they have been carefully rinsed.

irritable bowel syndrome

17. Chewing gum

Chewing gum often contains artificial sweeteners that make symptoms worse. Moreover, people often swallow air while chewing gum, and that can cause intestinal gas.

18. Spicy food

Spicy foods are often made with red chili peppers containing capsaicin, which can cause stomach pain and increase the GI tract’s motility. Capsaicin can cause abdominal pain and burn, even in people who don’t have irritable bowel syndrome.

19. Foods with lots of fiber

Fiber is one of the more ambiguous items on the list. Some patients have found that it can relieve their symptoms, while others find it makes them worse. A large part of the problem is several different types of fiber. Soluble fiber, for example, slows movement in the digestive tract, which can help people with diarrhea, while insoluble fiber has the opposite effect and can thus help people with constipation. Their viscosity and fermentability can also categorize fibers. Also, eating too much of any fiber can increase bloating and gas. A patient who wants to increase their fiber consumption should do so gradually.

20. Corn

Corn contains a lot of fiber and sugar, and it is harder to digest than most vegetables. While processed foods should usually be avoided, IBS patients who love corn should consider foods like creamed corn or corn bran easier to digest.

20 Foods That May Improve Your Irritable Bowel Syndrome

irritable bowel syndrome

Now that you know the foods to avoid to calm your IBS, you might be wondering what’s up next on your menu. Here, we share foods proven to help calm down the inflammation in your stomach.

Rest assured, you can eat a wide assortment of foods even if you suffer from IBS. Pick fresh vegetables and fruits if you can, but canned or frozen vegetables and fruits are sometimes healthy alternatives. Be sure to read the label to see if added sugar or salt exists.  Avoid eating processed foods. You may need to cut back on highly spiced foods, too.

This list of foods that calm IBS is divided into five groups: vegetables, fruits, grains, meats, and dairy.


Steam or roast these fresh vegetables in the oven with some olive oil and sea salt drizzled on top. Throw some fresh veggies into a salad or chop them up and top a bowl of brown rice. It’s best not to eat too many raw vegetables if you have IBS since raw vegetables can cause more bloating, gas, or discomfort.

  • Carrots-Carrots are high in beta carotene. They’re also high in fiber. Studies show that eating carrots lowers your chance of getting gastric cancer. Steam or saute them with olive oil or throw them into a fresh salad.
  • Green beans-Eat them fresh or frozen. Steam them and top with sliced almonds.
  • Bok choy-Stir fry bok choy with carrots and other veggies and your choice of meat.
  • Lettuce-Some people with IBS claim they can’t eat lettuce, but other people find it helps them stay regular if they have IBS with constipation. If you notice lettuce bothers your gut, eliminate it for a month or two, then try it again. Sometimes a little break from a specific food resets your gut enough that you can add it back into your diet.
  • Tomato-Tomatoes are high in vitamin C. Chop and saute the tomatoes, then throw them on top of a bowl of gluten-free pasta with some grated parmesan cheese.
Learn how to grow tomatoes at home.


These fruits are great additions to your morning smoothie or on top of your bowl of oatmeal for breakfast. Most berries except for blackberries are safe for IBS.

  • Oranges-Oranges are packed with vitamin C. They’re great or juicing.
  • Melons-Melons are sweet and delicious. They’re perfect for throwing into your smoothie or eating during your mid-morning snack.
  • Grapes-Freeze these little balls of goodness for a sweet, healthy treat in the evening when you’re craving ice cream.
  • Bananas- Bananas are a smoothie’s best friend. Add almond milk and some berries for a delicious and nutritious morning smoothie.
  • Blueberries or strawberries- These delicious berries are great for a snack or to top your morning oatmeal. Both fresh or frozen berries are healthy as long as sugar hasn’t been added to the frozen berries.


You don’t need to avoid fiber if you have IBS,  but you need to choose the right kind of fiber, especially if you suffer from IBS with diarrhea. Gluten makes IBS worse, so you’ll need to avoid it. Fortunately, there are lots of gluten-free foods available.

  • Oatmeal-Oatmeal is a superfood for IBS sufferers. It calms down your gut, preventing both constipation and diarrhea. It’s also a good source of protein.
  • Brown rice-Whole grain brown rice is rich in Vitamin B6, magnesium, phosphorus, selenium, and niacin.
  • Quinoa-Quinoa is a grain. The seeds are rich in protein and B vitamins. Cook it as you would rice. It’s the perfect side dish or main dish for any meal.
  • Gluten-free bread and pasta- There’s a huge variety of gluten-free products today. Be sure to read the labels to make sure what you’re buying is truly gluten-free and not filled with sugar or salt.
  • Corn meal-Corn meal can be used in muffins, pancakes, or bread.

Meats and eggs

Meat is one food group that doesn’t seem to stir up IBS symptoms. Preparation is key, though. Instead of frying, it’s best to roast, grill, or saute these meats in olive oil. You can eat healthy by eating smaller amounts of meat in your diet. Because it’s so high in amino acids and protein, you do not need to eliminate meat from your diet.

  • Beef-Beef is a versatile meat. It’s best to eat small amounts of beef to stay healthy. Studies reveal that eating a lot of red meat leads to health problems and a shorter life.
  • Pork-Pork is economical meat. Prepare in the crockpot or grill. Just be sure it’s cooked completely to 145 degrees Fahrenheit internally.
  • Chicken-Chicken is lower in fat than beef or pork. It’s great grilled, sauteed, or baked.
  • Fish-High in omega-3 fatty acids, which benefits your brain. Salmon, mackerel, herring, trout, sardines, and tuna have the highest amounts of omega-three.
  • Eggs-Eggs are a great source of protein. Boil or poach them for breakfast. Add scrambled eggs to your stir-fried rice dish for dinner. You can also make egg salad with IBS-safe mayo, mustard, and chopped-up dill pickles. Spread on gluten-free crackers or bread for lunch.


Dairy products are high in calcium and protein. Cheeses that are fermented or aged are best for good gut health. Avoid mild, creamy cheeses since these may cause diarrhea or constipation.

  • Sharp cheeses-Aged sharp cheeses won’t stir up IBS. They’re delicious or put into dishes with pasta or potatoes.
  • Brie-Brie is a delicious cheese named after a region in France. Spread it on rice crackers or gluten-free toast for a mid-afternoon snack.
  • Feta-Crumble feta on top of salads or a bowl of brown rice to add protein to the dish.
  • Lactose-free milk, almond, coconut, or rice milk. These plant-based kinds of milk add flavor and are healthier than cow’s milk. Use them as you would cow milk in baking, cooking, or on top of cereal.
Read about the amazing benefits of eating yogurt.

Other foods and spices to avoid if you have irritable bowel syndrome

You don’t necessarily need to avoid spices. Just use them sparingly. If the spices or other food upsets your gut, avoid them.

  • Olives

Olives are grown in warm climates. The fantastic flavor of olives comes from the salty brine they’re prepared in. Olives have an anti-inflammatory effect on your body. Put them on salads, on top of rice, or pop a couple in your mouth for a quick snack. Or mix chopped olives and olive oil for a dipping sauce.

  • Almonds

Almonds are full of vitamins and minerals. Top your favorite grilled fish with sliced or crushed almonds for extra flavor. Or throw some into your smoothie for a bit of crunch.

  • Peanut butter

High in protein and big on taste, peanut butter can be used in baking, cooking, or simply a snack. Throw some on top of your smoothie to add a crunchy texture.

Turmeric contains curcumin, which has all kinds of health benefits. Researchers found it can prevent heart disease, cancer, and Alzheimer’s disease. It’s also an anti-inflammatory. Sprinkle turmeric on top of popcorn for a naturally nutty flavor.

  • Ginger

Here’s another pungent spice that adds flavor to smoothies, vegetable dishes, and soups. Ginger makes a delightful tea, too.

  • Mint

Mint fresh flavor delights your palate in salads or stir-fries. Grow it in a pot outside, so it’s law ays available for hot or iced tea in the summer.

  • Cumin

Cumin seeds are high in antioxidants. This spice helps fight bacteria and can lower your blood sugar. It also has anti-inflammatory effects, so it’s a natural way to reduce arthritis or joint pain.

Learn more about the lesser-known probiotic kefir.

Final Thoughts On How Foods Impact Irritable Bowel Syndrome

Irritable bowel syndrome affects hundreds of people today. It’s a debilitating and embarrassing condition that can affect your social life, work, and family life.  Fortunately, IBS can be controlled by diet. Certain foods will reset your gut, allowing it to settle down and function properly.

You will find a wide variety of vegetables, fruits, meats, dairy, and spices that you can eat on an IBS diet. Many people prefer to stay on this long-term diet to improve their health. If you suffer from IBS, it’s tempting to feel discouraged. Take heart. It’s possible to enjoy food and be healthy again.