MedicalLexicon.com’s medical dictionary describes irritable bowel syndrome, or IBS, as “uncoordinated and inefficient contractions of the large intestine.” According to FamilyDoctor.org, the intestines squeeze too hard or not hard enough, causing food to move too quickly or too slowly through the intestines. Foods themselves don’t cause IBS, but they can worsen the symptoms. To stave off the pain and discomfort of IBS, common trigger foods should be eliminated from the diet.
According to the National Institutes of Health, alcohol, caffeinated drinks and carbonated beverages often produce IBS symptoms, such as abdominal pain or discomfort, diarrhea and constipation.
Dairy products like cheese, milk, ice cream and butter can worsen IBS symptoms. Even for those who are not lactose intolerant, according to the National Institutes of Health, dairy products can cause negative reactions, such as abdominal pain, bloating and discomfort. Dairy components such as lactose, milk fat, casein and whey can be problematic.
The fat and caffeine in hard chocolate can cause colonic contractions, resulting in pain and discomfort. According to HelpForIBS.com, cocoa powder may be more tolerable to the gastrointestinal system for IBS sufferers because it is fat-free. Substitute cocoa powder for hard chocolate in recipes.
All fats stimulate colonic contractions that can cause painful abdominal cramping. According to the American College of Gastroenterology, IBS sufferers should substitute high-fiber foods for high-fat and low-fiber foods. Foods that are high in fats include meats, poultry skin, nuts, avocados, shortenings, margarine, butter, cheese, cream, whole milk, vegetable oils, deep-fried foods, many candies, ice cream and chocolate.
Some sugars and sugar substitutes can cause abdominal cramping, bloating, gas and other intestinal discomforts. Medical professionals at the University of Maryland Medical Center recommend avoiding refined carbohydrates like white rice, pastas, white breads and white flour, which convert to sugar in the body. Some people also may have a problem with the sugar substitutes mannitol and sorbitol. According to the University of Iowa Hospitals and Clinics, fructose can be especially problematic.
Yeasts and Molds
The jury is out on whether or not yeast causes IBS symptoms. Your body is different than anyone else's, so you may find that yeast is a problem for you, but not for others with IBS. A study in the August 2005 issue of "Gut" states that it is unlikely that yeast is a trigger for IBS. Yeast overgrowth, or candida, can cause IBS symptoms. Among the yeast- and mold-producing foods to avoid are yeast breads, wine, beer, mushrooms, cheeses and dried fruits. Sugars and refined carbohydrates also feed yeast and can aggravate IBS. The 2012 issue of "BMC Gastroenterology" explains that while you may not be allergic to yeast, you may be sensitive to it.
Wheat and Gluten
Some people find that avoiding wheat improves IBS symptoms. Others find that they must eliminate all gluten products, which include wheat, barley, rye, spelt and sometimes oats. If you decide to go gluten-free, following a celiac diet can help. Since wheat and gluten are found in so many products, it is important to read labels. Gluten and wheat can be found in soups, sausages, processed meats, frozen prepared meals and potato chips.
Fruits and Vegetables
According to the University of Pittsburgh Medical Center, certain vegetables like oats, peas and beans, as well as fresh fruits, are high in soluble fiber and can irritate the bowels if added to the diet too quickly. Symptoms include gas, bloating, cramping or diarrhea. If diarrhea persists, first try cooked fruits and vegetables before slowly introducing raw foods to your diet.