Symptoms of irritable bowel syndrome (IBS) have something to do with patients' diet. According to a review, foods with fermentable oligosaccharides, disaccharides, monosaccharides and polyols can reduce symptoms of irritable bowel syndrome.  Soluble fiber like pectin improves constipation but increase bloating and abdominal pain. (In the writer's opinion, it is very unlikely for pectin in a small dose to cause any bloating and abdominal pain.)No dietary guidelines are available specifically for patients with irritable bowel syndroms, but it is generally believed that greasy foods, dairy products, many carbohydrates, caffeine and alcohol should be avoided.  Carbohydrate malabsorption is frequently linked to symptoms of irritable bowel syndrome.  (David Liu, PHD)Mearin F, Peña E, Balboa A.  [Importance of diet in irritable bowel syndrome]. [Article in Spanish]  Gastroenterol Hepatol. 2014 May;37(5):302-10.