question: Irritable Bowel Syndrome (IBS) (How can my diet treat the symptoms of IBS?): Eating smaller meals more often, or eating smaller portions, may help your irritable bowel syndrome (IBS) symptoms. Large meals can cause cramping and diarrhea if you have IBS.Eating foods that are low in fat and high in carbohydrates, such as pasta, rice, whole-grain breads and cereals, fruits, and vegetables, may help.Fiber may improve constipation symptoms caused by IBS because it makes stool soft and easier to pass. Fiber is a part of foods such as whole-grain breads and cereals, beans, fruits, and vegetables. The U.S. Department of Agriculture and U.S. Department of Health and Human Services state in its Dietary Guidelines for Americans, 2010 (PDF, 2.963 MB) that adults should get 22 to 34 grams of fiber a day.3While fiber may help constipation, it may not reduce the abdominal discomfort or pain of IBS. In fact, some people with IBS may feel a bit more abdominal discomfort after adding more fiber to their diet. Add foods with fiber to your diet a little at a time to let your body get used to them. Too much fiber at once can cause gas, which can trigger symptoms in people with IBS. Adding fiber to your diet slowly, by 2 to 3 grams a day, may help prevent gas and bloating.