IBS and food is a challenging puzzle to sort out because foods that trigger IBS symptoms are not true allergies or even sensitivities, and may not cause symptoms every time they are eaten. This makes it very challenging to figure out what to eat and what to avoid.
Foods cause symptoms in someone with IBS partly because of imbalances in bacteria and partly because of heightened sensitivity and awareness to gas build up in those who experience IBS symptoms. The Low FODMAP diet (which stands for fermented oligosaccharides, disaccharides, monosaccharides and polyols) removes undigestible sugars from the diet, that when eaten in excess or when the digestive symptom is hypersensitive, will cause gas build-up, water to move into the bowel and as a result and symptoms such as pain, bloating and diarrhea.
The diet is partly used as a “test” to determine if symptoms are related to IBS and partly as a short term treatment solution to begin to bring improvement in symptoms. The first phase of the diet plan removes foods that have these non-digestible sugars in them. This helps reduce gas formation and water logging of the stool – which in turn helps reduce symptoms related to IBS such as abdominal pain, gas and diarrhea.
This first phase is a 4-8 week testing/treatment phase. If you respond it does not mean that these foods will be taken out of your diet forever. It helps confirm the diagnosis of IBS and helps guide treatment solutions. You will likely be able to enjoy these foods at a later date.
The second stage of the diet will depend on your progress with the first, but the goals include increasing variety and testing out various foods and sugars contained in those foods to see what you can tolerate while remaining symptom free.
High FODMAP foods - the foods to avoid
Fruit: Apple, apricot, avocado, blackberry, cherry, longonberry, mango, nectarine, pear, plum, prune, canned fruit, watermelon. Also large servings of fruit, fruit juices, dried fruit
Vegetables: Artichoke, asparagus, beet, broccoli, brussels sprouts, cabbage, corn, fennel, garlic, green bell peppers, leek, mushrooms, okra, onion (all types), shallot, spring onion.
Dairy: Milk from cow, goat, sheep, ice cream, yogurt, cottage cheese, ricotta, marscapone
Grains: Wheat, rye.
Legumes: Beans, chickpeas, lentils, kidney beans, soy beans.
Sweeteners: Fructose, high fructose corn syrup, corn syrup, honey, sorbitol, mannitol, isomalt, maltitol, xylitol.
Miscellaneous: Chickory, dandelion inulin, pistachio
Low FODMAP foods - the foods to emphasize
Fruit: Banana, blueberry, boysenberry, canteloupe, cranberry, durian, grape, grapefruit, honeydew, melon, kiwi, lemon, lime, orange, passionfruit, raspberry, rhubarb, rockmelon, star anise, strawberry, tangelo.
Vegetables: Alfalfa, bamboo shoots, bean shoots, bok choy, carrot, celery, eggplant, endive, ginger, green beans, lettuce, olives, parsnip, potato, pumpkin, red pepper, silver beet, spinach, squash, sweet potato, taro, tomato, turnip, yam, zucchini.
Herbs: Basil, chili, coriander, ginger, lemongrass, marjoram, mint, oregano, parsley, rosemary, thyme.
Dairy: Lactose-free milk, oat milk, rice milk, hard cheeses, brie, camembert, dairy-free gelato and sorbet,
Grains: Gluten-free bread, 100% spelt bread, rice, oats, polenta, arrowroot, millet, psyllium, quinoa, sorghum, tapioca.
Legumes: Tofu
Sweeteners: Sugar, maple syrup, molasses (all in small quantities).