What is Irritable Bowel Syndrome?
Our digestive tract plays an important role in our health. The primary functions of our digestive system are to digest food and extract the nutrients from the food we eat.
There are a number of disorders that can affect the proper functioning of our digestive system including coeliac disease, Crohn’s disease, ulcerative colitis, bowel cancer as well as Irritable Bowel Syndrome (IBS).
IBS is a common functional gastrointestinal disorder that can affect one in seven adults. Symptoms of IBS can include wind, constipation, bloating, tummy pain, constipation and/or diarrhoea. These issues can cause someone a lot of stress and interferes with their daily lives. It is vital to discuss the symptoms of IBS with your medical professional to exclude other serious gastrointestinal symptoms such as inflammatory bowel disease, coeliac disease and bowel cancer. Also, it is interesting to note that endometriosis can mimic the symptoms of IBS. Therefore it is really important not to ‘self-diagnose’ and if these are issues you are experiencing, seek medical advice.
What is the Low FODMAP Diet?
FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. Foods high in FODMAPs include apples, onions, garlic, mushrooms and milk and yoghurt. These carbohydrates are poorly absorbed in the intestine due to a range of reasons. These may include slow transport, reduced enzyme activity or molecules being too large to pass across the intestine.
As a result of poor absorption, FODMAPs pass through to the large intestine undigested. The bacteria in the large intestine digest and ferment the undigested carbohydrates and produce gas. FODMAPs also have an osmotic effect, which means that they draw fluid in the gut, resulting in increased water in the bowel. This can be particularly problematic for many sufferers of IBS.
FODMAP digestion or lack thereof differs between individuals, as do the symptoms. Further, while FODMAPs are mostly poorly absorbed in all people, it is particularly problematic for those with a sensitive gut.
There is no diagnostic test for IBS, although breath tests are available to identify some, but not all problematic FODMAPs.
Why do I need to follow the FODMAP diet?
The FODMAP diet will allow you to identify which group/s of carbohydrates may be responsible for your symptoms.
How do I follow the diet?
It is crucial to develop a strategy and plan ahead before commencing the diet. An Accredited Practising Dietitian can assist you to ensure that your diet is free of all FODMAPs and that it’s nutritionally complete. Your dietitian can also assist you to develop simple and appetizing meal plans.
What foods can’t I eat on the diet?
- Oligosaccharides – wheat, rye, onions, artichokes, asparagus, leek, beetroot, legumes, beans, lentils, chickpeas, cabbage and Brussels sprouts
- Lactose – milk, ice cream, yoghurt, custard, dairy desserts, condensed and evaporated milk, milk powder, margarine and cottage, ricotta and cream cheeses
- Fructose – honey, apples, mangoes, watermelon, prunes, figs and high fructose corn syrup
- Polyols – apples, avocado, mushrooms, cherries, lychees, nectarines, pears, plums, sorbitol, mannitol, xylitol, maltitol and isomalt
How can I meet my nutrient requirements while following the diet?
It is important to ensure that you still follow a healthy balanced diet while following the low FODMAP eating plan. That means including foods from all five food groups. Here is a guide to help you ensure that you tick all the nutritional boxes:
- Vegetables – aim for 5-7 serves a day
- Bread, cereals, rice and pasta/noodles – aim for at least 4 serves a day
- Fruit – at least 2 serves a day
- Meat and alternatives – 1-2 serves a day
- Dairy – 3-4 serves a day
- Limit your intake of fatty foods, caffeine and alcohol, as these are known triggers for IBS-type symptoms.
Low FODMAP shopping guide
Vegetables – alfalfa, bamboo shoots, green beans, bok choy, carrot, eggplant, endive, cucumber, ginger, capsicum, potato, rocket, spinach, tomatoes and zucchinis;
Fruit – bananas, grapes, mandarins, limes, passionfruit, pineapple, cantaloupe;
Dairy – lactose-free milk, yoghurt and ice cream, hard yellow cheese, rice milk, soy milk (made with soy protein, rather than soybean);
Meat and alternatives – chicken, lamb, beef, kangaroo, chicken, fish, eggs, tofu and tempeh;
Bread, cereals, rice and noodles – gluten-free bread and pasta, rice, quinoa, polenta, cornflour, rice base cereals;
Nuts and seeds – macadamias, pine nuts, peanuts, walnuts, sesame seeds and pumpkin seeds.
Sample meal plan:
2 x slices of gluten-free whole grain toast with eggs and wilted spinach or gluten-free cereal with lactose-free milk and a banana
Lactose-free yoghurt or corn cakes with peanut butter
Sandwich with gluten-free bread and sliced ham, tasty cheese, lettuce and tomato or tuna salad with lettuce, tomato, cucumber and carrot
2 x kiwi fruit or 1 x cup of popcorn
Porterhouse steak served with mashed potato and roasted vegetables or tofu stir fry with vegetables and rice noodles
Lactose-free ice cream and strawberries or 2 x squares of dark chocolate
Is this a lifetime diet?
No. The diet is usually recommended for 2-6 weeks or until your symptoms subside. Once your symptoms are no longer present you can begin the re-introduction phase. Your dietitian can help to advise you which foods you can reintroduce.
Can I still eat out at restaurants?
Eating out can prove challenging, however, you don’t necessarily have to go without. Many restaurants can be accommodating for those people with intolerances; choosing plain foods such as meat and fish with vegetables and potatoes or rice is a safe bet. Japanese is one cuisine with many low FODMAP options. Alternatively, there are a number of Italian restaurants that will offer a gluten-free pasta and pizza option – just be mindful of the sauces and toppings.
What if I break the diet?
It is best to stick to the low FODMAP diet as best as you can. However, if you do break the diet, just be sure to return to a stringent form of the diet as soon as you can.
How do I know which FODMAPs are problematic for me?
The ‘challenge’ phase or reintroduction phase will shed some light on which FODMAPs may be the cause of your tummy symptoms.
Your diet can now be tailored to ensure that you reduce your intake of any high problematic FODMAP foods. Further, it should be noted that while IBS-type symptoms are uncomfortable for many, there is no cause for alarm if they do continue to persist. The ingestion of any troublesome high FODMAP food will not result in any structural damage. This is obviously very different to those who suffer from coeliac disease in which any ingestion of gluten is likely to cause damage to the villi lining of the small intestine. So, rest assured that if you do decide to enjoy a particular food that is high in a problematic FODMAP, you will simply have to deal with the uncomfortable symptoms and not be concerned about any associated damage.
- FODMAPs are a group of carbohydrates commonly found in everyday foods
- Dietary restriction of FODMAPs has been clinically shown to reduce IBS symptoms
- Working with a dietitian to develop a personal eating plan can ensure that you follow a well-balanced and nutritious diet
- This is not a lifetime diet. Once symptoms subside, foods can be gradually re-introduced in order to discover which FODMAP/s may be responsible for the symptoms.
For more information check out the Monash University Low FODMAP Diet Guide and phone app.