Irritable Bowel Syndrome Made Manageable: Discover the Low FODMAP Diet and How It Works

Managing Irritable Bowel Syndrome (IBS) can be challenging, with symptoms such as cramping, diarrhea, gas, and bloating impacting daily life. While there are various treatments available, dietary changes, particularly the adoption of the low FODMAP diet, are crucial. This article examines how this dietary approach can improve the quality of life for individuals managing IBS.

Try a FODMAPs diet to manage Irritable Bowel Syndrome Symptoms

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with symptoms like cramping, diarrhea, gas and bloating, it's no surprise that living with IBS can have a significant effect on a person's quality of life.

Diet is one way people manage IBS symptoms. A common treatment approach is to avoid the foods that trigger symptoms. Another diet for IBS, developed in Australia, is having a lot of success in managing IBS symptoms. It's called the low FODMAP diet.

What is the low FODMAP diet? 

FODMAP stands for "Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols". These fermentable short-chain carbohydrates are prevalent in the diet.

• Oligosaccharides: fructans and galacto-oligosaccharides (GOS)
• Disaccharides: lactose
• Monosaccharides: fructose
• Polyols: sorbitol and mannitol

Researchers discovered that the small intestine does not absorb FODMAPs very well. They increase the amount of fluid in the bowel. They also create more gas. That's because bacteria in the colon they are easily fermented by colonic bacteria. The increased fluid and gas in the bowel leads to bloating and changes in the speed with which food is digested. This results in gas, pain and diarrhea. Eating less of these types of carbohydrates should decrease these symptoms.

So far, studies have shown that a low FODMAP diet improves IBS symptoms. One study even found that 76% of IBS patients following the diet reported improvement with their symptoms.

Eat less of these foods:

Lactose

• Cow's milk, yogurt, pudding, custard, ice cream, cottage cheese, ricotta cheese and mascarpone

Fructose

• Fruits, such as apples, pears, peaches, cherries, mangoes, pears and watermelon
• Sweeteners, such as honey and agave nectar
• Products with high fructose corn syrup

Fructans

• Vegetables, such as artichokes, asparagus, Brussels sprouts, broccoli, beetroot, garlic and onions
• Grains such as wheat and rye
• Added fiber, such as inulin

GOS

• Chickpeas, lentils, kidney beans and soy products
• Vegetables, such as broccoli

Polyols

• Fruits, such as apples, apricots, blackberries, cherries, nectarines, pears, peaches, plums and watermelon
• Vegetables, such as cauliflower, mushrooms and snow peas
• Sweeteners, such as sorbitol, mannitol, xylitol, maltitol and isomalt found in sugar-free gum and mints, and cough medicines and drops

Eat more of these foods:

• Dairy: Lactose-free milk, rice milk, almond milk, coconut milk, lactose-free yogurt; hard cheeses such as feta and brie
• Fruit: Bananas, blueberries, cantaloupe, grapefruit, honeydew, kiwi, lemon, lime, oranges and strawberries
• Vegetables: Bamboo shoots, bean sprouts, bok choy, carrots, chives, cucumbers, eggplant, ginger, lettuce, olives, parsnips, potatoes, spring onions and turnips
• Protein: Beef, pork, chicken, fish, eggs and tofu
• Nuts/seeds (limit to 10-15 each): Almonds, macadamia, peanuts, pine nuts and walnuts
• Grains: Oat, oat bran, rice bran, gluten-free pasta, such as rice, corn, quinoa, white rice, corn flour and quinoa

The idea behind the low FODMAPs diet is to only limit the problematic foods in a category — not all of them. (After all, they do have health benefits.) You may tolerate some foods better than others.

Meet with a registered dietician if you are considering this diet. It's important to make sure your eating plan is safe and healthy. He or she will have you eliminate FODMAPs from your diet. Then you gradually add the carbohydrates back in one at a time and monitor your symptoms. A food diary and symptom chart may be helpful tools.

The bottom line

The low FODMAP diet has shown potential in helping people with IBS. Some health professionals believe it's too restrictive. Proponents of the diet report that people stick with it because of how it improves their quality of life.

Managing IBS symptoms is possible with the low FODMAP diet by limiting specific carbs. While it may be restrictive, the relief often justifies the effort. Consulting a dietitian ensures a safe, tailored approach. Reintroducing foods and observing symptoms can significantly boost comfort and life quality.

This article is part of our collaboration with Harvard Health Publishing, a trusted source of medical expertise from Harvard Medical School. Content has been adapted for local audiences.

Copyright © 2025 by Harvard University. Original work prepared by Harvard Health Publishing. This content is for informational purposes only and does not replace professional medical advice, and do not represent the views of Manulife (Singapore) Pte. Ltd.