Fructose:
Fructose is a type of sugar found in fruits, honey, and some vegetables. It is also added to many processed foods. Fructose can cause bloating, gas, and diarrhea in people with IBS.

This is because fructose is absorbed differently than other types of sugar. It is absorbed in the small intestine, but it can also be absorbed in the large intestine. When fructose is absorbed in the large intestine, it can cause bloating, gas, and diarrhea.

Lactose:
Lactose is a type of sugar found in milk and dairy products. It is broken down by an enzyme called lactase. People who are lactose intolerant do not produce enough lactase, which can cause bloating, gas, and diarrhea after consuming dairy products.

Lactose intolerance is a common condition. It is estimated that about 65% of the world's population is lactose intolerant. Lactose intolerance is more common in people of Asian, African, and Hispanic descent.

Gluten:
Gluten is a protein found in wheat, barley, and rye. It can cause bloating, gas, and diarrhea in people with celiac disease or gluten intolerance.

Celiac disease is an autoimmune disorder. It is caused by a reaction to gluten. When people with celiac disease eat gluten, their immune system attacks the lining of their small intestine. This can cause damage to the small intestine and make it difficult to absorb nutrients.

Gluten intolerance is a condition that is similar to celiac disease. However, people with gluten intolerance do not have an autoimmune reaction to gluten. They still experience symptoms when they eat gluten, but these symptoms are not as severe as the symptoms of celiac disease.

Fat:
Fat can slow down digestion, which can cause bloating, gas, and diarrhea in people with IBS. It is important to limit the amount of fat in your diet if you have IBS.

Fat can also trigger the release of bile, which can cause diarrhea. Bile is a fluid that is produced by the liver and stored in the gallbladder. It helps to digest fats. When bile is released, it can cause diarrhea.
Also see Bile Acid Malabsorption (BAM)


Fat is important for vitamins and hormones. Fats are a type of macronutrient that are essential for human health. They provide energy, help to absorb vitamins, and play a role in hormone production.
Some vitamins are fat-soluble, which means that they can only be absorbed by the body with the help of fat. These vitamins include vitamins A, D, E, and K. Fat-soluble vitamins are important for a variety of functions, including vision, bone health, immune function, and blood clotting.
Fats are also important for the production of hormones. Hormones are chemical messengers that regulate a variety of bodily functions, including growth, development, reproduction, and metabolism. Some hormones, such as testosterone and estrogen, are made from cholesterol, a type of fat.

Caffeine:
Caffeine is a stimulant that can irritate the lining of the gut. It can cause bloating, gas, and diarrhea in people with IBS.

Caffeine can also increase the production of stomach acid. This can irritate the lining of the stomach and cause diarrhea.

Alcohol:
Alcohol can irritate the lining of the gut and cause bloating, gas, and diarrhea in people with IBS. Alcohol can also dehydrate the body, which can make IBS symptoms worse.

Alcohol can irritate the lining of the gut in a few ways. First, alcohol can increase the production of stomach acid. This can irritate the lining of the stomach and cause diarrhea. Second, alcohol can damage the lining of the small intestine. This can make it difficult to absorb nutrients, which can lead to bloating and gas. Third, alcohol can increase the permeability of the gut lining. This means that toxins and bacteria can leak from the gut into the bloodstream. This can cause inflammation and other problems.

Carbonated beverages:
Carbonated beverages can cause bloating and gas in people with IBS. This is because the carbon dioxide in the beverages can be trapped in the stomach and intestines. This can cause pressure and discomfort.

Carbonated beverages contain carbon dioxide, which is a gas that is dissolved in the liquid. When you drink a carbonated beverage, the carbon dioxide gas comes out of solution and forms bubbles. These bubbles can get trapped in your stomach and intestines, which can cause bloating and gas.

Spicy foods:
Spicy foods can irritate the lining of the gut and cause bloating, gas, and diarrhea in people with IBS. This is because spicy foods contain capsaicin, which is a compound that can irritate the lining of the gut.

Capsaicin is the compound that gives chili peppers their heat. It works by binding to receptors in the lining of the gut. These receptors send signals to the brain that there is something hot in the gut. This can cause the gut to contract, which can lead to bloating, gas, and diarrhea.

Citrus fruits:
Citrus fruits, such as oranges, grapefruits, and lemons, can cause bloating, gas, and diarrhea in people with IBS. This is because citrus fruits contain sorbitol, a type of sugar alcohol that can cause bloating and gas.

Sorbitol is a type of sugar alcohol that is found in many fruits and vegetables. It is also added to many processed foods as a sweetener. Sorbitol is not absorbed well by the body, so it passes through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Tomatoes:
Tomatoes can cause bloating, gas, and diarrhea in people with IBS. This is because tomatoes contain lycopene, a compound that can irritate the lining of the gut.

Lycopene is an antioxidant that is found in tomatoes and other red fruits and vegetables. It is thought to be beneficial for health, but it can also irritate the lining of the gut in people with IBS.

Onions:
Onions can cause bloating, gas, and diarrhea in people with IBS. This is because onions contain fructans, a type of fiber that can cause bloating and gas.

Fructans are a type of fiber that is found in many fruits and vegetables. They are also added to many processed foods as a prebiotic. Fructans are not absorbed well by the body, so they pass through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Garlic:
Garlic can cause bloating, gas, and diarrhea in people with IBS. This is because garlic contains fructans, a type of fiber that can cause bloating and gas.

Fructans are a type of fiber that is found in many fruits and vegetables. They are also added to many processed foods as a prebiotic. Fructans are not absorbed well by the body, so they pass through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Beans:
Beans are a good source of fiber, but they can also cause bloating, gas, and diarrhea in people with IBS. This is because beans contain oligosaccharides, a type of fiber that can cause bloating and gas.

Oligosaccharides are a type of fiber that is found in many beans and legumes. They are not absorbed well by the body, so they pass through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

If you have IBS, it is important to avoid foods that trigger your symptoms. If you are not sure which foods trigger your symptoms, you may want to keep a food journal. This will help you to track what you eat and how it makes you feel. Once you have identified the foods that trigger your symptoms, you can avoid them.

Broccoli:
Broccoli is a good source of fiber, but it can also cause bloating, gas, and diarrhea in people with IBS. This is because broccoli contains raffinose, a type of fiber that can cause bloating and gas.

Raffinose is a type of fiber that is found in many vegetables, including broccoli, cabbage, and Brussels sprouts. It is not absorbed well by the body, so it passes through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Cabbage:
Cabbage is a good source of fiber, but it can also cause bloating, gas, and diarrhea in people with IBS. This is because cabbage contains raffinose, a type of fiber that can cause bloating and gas.

Raffinose is a type of fiber that is found in many vegetables, including broccoli, cabbage, and Brussels sprouts. It is not absorbed well by the body, so it passes through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Kale:
Kale is a good source of fiber, but it can also cause bloating, gas, and diarrhea in people with IBS. This is because kale contains raffinose, a type of fiber that can cause bloating and gas.

Raffinose is a type of fiber that is found in many vegetables, including broccoli, cabbage, and Brussels sprouts. It is not absorbed well by the body, so it passes through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Carrots:
Carrots are a good source of fiber, but they can also cause bloating, gas, and diarrhea in people with IBS. This is because carrots contain pectin, a type of fiber that can cause bloating and gas.

Pectin is a type of fiber that is found in many fruits and vegetables, including carrots, apples, and pears. It is not absorbed well by the body, so it passes through the digestive system undigested. This can cause bloating, gas, and diarrhea in people with IBS.

Potatoes:
Potatoes are a good source of fiber, but they can also cause bloating, gas, and diarrhea in people with IBS. This is because potatoes contain resistant starch, a type of fiber that can cause bloating and gas.

Resistant starch is a type of fiber that is not digested by the small intestine. It passes through the small intestine and into the large intestine, where it is fermented by bacteria. This fermentation process can produce gas and bloating.

If you have IBS and you are sensitive to resistant starch, you may want to avoid potatoes. You may also want to avoid other foods that contain resistant starch, such as green bananas, cooked legumes, and whole grains.

Yogurt:
Yogurt is a good source of probiotics, which are live bacteria that are beneficial for the gut. However, yogurt can also contain lactose. If you are lactose intolerant, you should avoid yogurt.

Lactose is a type of sugar that is found in milk and dairy products. It is broken down by an enzyme called lactase. People who are lactose intolerant do not produce enough lactase, which can cause bloating, gas, and diarrhea after consuming dairy products.

If you are lactose intolerant, you may want to choose yogurt that is labeled as "lactose-free." Lactose-free yogurt has had the lactose removed, so it is safe for people with lactose intolerance to eat.

Soda:
Soda is a carbonated beverage that is made with water, sugar, and carbon dioxide. It can cause bloating and gas in people with IBS. This is because the carbon dioxide in the soda can be trapped in the stomach and intestines. This can cause pressure and discomfort.

Soda can also dehydrate the body, which can make IBS symptoms worse. If you have IBS, you should avoid soda. You may want to choose water, unsweetened tea, or coffee instead.