Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, affecting 10-20% of the population. (1) It is a benign but troublesome condition featuring symptoms such as (1, 2)
These symptoms fluctuate in severity from day to day, making it a turbulent condition. (3) IBS is a chronic condition and has to date no known etiology or cure. (2, 4) Genetics appear to play a role in susceptibility to IBS. (2) The high prevalence makes this condition a major contributor to reduced quality of life, work absenteeism and impaired social functioning. (4)
Screening, Tests & Diagnosis
If IBS is suspected, it is important that a physician rule out other conditions, such as coeliac disease, ulcerative colitis, food chemical sensitivity, gastrointestinal infections, endometriosis and ovarian cancer that can mimic IBS symptoms (3) These other conditions will be managed very differently to IBS.
IBS is diagnosed using the ‘Rome III’ criteria if an individual has suffered symptoms of a functional gut disorder for at least six months and have experienced for at least three months of the year: (4-6)
A hydrogen and/or methane breath test will be completed to determine malabsorption of fructose, lactose and/or sorbitol. (5, 7) Although some of the gas produced in the large bowel is passed out as flatus, most of it transfers across the lining of the large bowel and into the blood stream where it dissolves into the blood. (3) Blood is carried to the lungs, and the gas is breathed out via the lungs (3) The results of this test will determine the modifications required in an individuals diet.
Symptoms of IBS are most commonly triggered by a food intolerance; therefore dietary modifications have emerged as the first-line treatment. (2) Dietary therapy, in particular the low FODMAP diet has now developed as an evidence-based approach to managing IBS symptoms, effective in 75% of the IBS population. (2, 4, 5) FODMAPs are short chain carbohydrates that are poorly absorbed in the small intestine, are rapidly fermented by bacteria and create gas, and have a high osmotic effect, drawing fluid into the gut. (5, 7)
The FODMAPs acronym:
Oligosaccharides (fructans & galacto-oligosaccharides/GOS)
Monosaccharides (fructose in excess of glucose)
Polyols (eg. sorbitol, mannitol, xylitol, maltitol)
FODMAPs Dietary Intervention
Generally it is either a dietitian or gastroenterologist that will recommend a low FODMAP individualised diet for 6-8 weeks until they are symptom free. They would then guide their client through a FODMAP challenge, where foods are reintroduced strategically to determine the FODMAP intolerance. This often takes at least 6-8 weeks. It is important any FODMAP challenge is undertaken with the guidance of a health professional to avoid unnecessary elimination of foods in the diet long term.
Generally, all individuals diagnosed with IBS are advised by health professionals to avoid high fructan, GOS and mannitol containing foods. (2, 8) Further dietary modifications will be made to lactose, fructose and sorbitol only if indicated by the breath test. (2, 7) Each individual that has gone through this diagnosis and dietary prescription process will be given resources with detailed information on which foods to avoid or limit in their diet. The Monash University App is a popular resource, which is updated as new information is released.
In our tables below, foods high in FODMAP content are highlighted utilising the macronutrient categories – low and high-energy carbohydrates, first class proteins, and ‘other’ to indicate discretionary choices. It is important to note that this is an evolving area, with the discovery of additional high & low FODMAP foods each week. Monash University currently has full time food technologists dedicated to analysing FODMAP content in their laboratory.
Practical Hints for better eating
Many of the recipes found in the transformationcookbook.com require very simple modifications to be appropriate for an individual with IBS. Often, removing or modifying the amount of onion consumed in a meal is all that is required to become FODMAP friendly. We use garlic and onion in many recipes to add flavour, so lack of flavour can be a common complaint with individuals following this diet. Some FODMAP friendly hints to flavour food include:
Transformationcookbook recipes can easily be modified depending on the intolerance. Use the appropriate substitutions in the tables above and consult your health professional.
An example a TCB Low FODMAP Meal Plan:
Meal 1 The 3 min Omlette
Meal 3 Healthy Chinese takeaway chicken – just omit onions
Meal 4 Rainbow muffin – simply omit onions
Meal 5 TCB Roast
Dessert: TCB Cobbler – just replace the peach with pawpaw or melon
Physically active individuals with IBS will face less symptoms, and symptom deterioration than those that are physically inactive. (9) It has been proposed that this is due to the stimulation and increased gastrointestinal motility when physical activity is undertaken. (9) In turn, colonic transit time is improved (less constipation), gas and bloating is reduced. (9, 10) Endurance athletes however often experience adverse effects such as prompting an urge to defecate, diarrhoea and gastrointestinal cramps. (9) As per the broader population, incorporating resistance training and vigorous cardio exercise are fantastic ‘doses’ of physical activity for successful primary treatment in IBS.
It is important to refer to a physician immediately for further investigation if an individual experiences: (11)
It appears that eating a healthy Western breakfast’ of milk with high-fibre cereals, whole grain bread with honey, washed down with apple juice, is perhaps the worst way to start off the day for an adult IBS patient, utilising the transformationcookbook.com meal planner for hundreds of breakfast substitutions to help manage symptoms of IBS! (12)
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2. Shepherd SG, Peter. Food Intolerance Management Plan. Melbourne: Pengiun Group; 2011.
3. Shepherd S. Low FODMAP Recipes. Melbourne: Penguin Group; 2013.
4. Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67-75.e5.
5. Gibson PR, Shepherd SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. Journal of Gastroenterology & Hepatology. 2010;25(2):252-8.
6. Lomangino K. The low-FODMAP diet: a new treatment approach for irritable bowel syndrome. Clinical Nutrition Insight. 2012;38(6):1-4.
7. Shepherd SJ, Gibson PR. Fructose malabsorption and symptoms of irritable bowel syndrome: guidelines for effective dietary management. Journal Of The American Dietetic Association. 2006;106(10):1631-9.
8. Muir JG, Shepherd SJ, Rosella O, Rose R, Barrett JS, Gibson PR. Fructan and free fructose content of common Australian vegetables and fruit. Journal Of Agricultural And Food Chemistry. 2007;55(16):6619-27.
9. Johannesson E, Simrén M, Strid H, Bajor A, Sadik R. Physical activity improves symptoms in irritable bowel syndrome: a randomized controlled trial. The American Journal Of Gastroenterology. 2011;106(5):915-22.
10. Lewis SJ, Heaton KW. Stool Form Scale as a Useful Guide to Intestinal Transit Time. Scandinavian Journal of Gastroenterology. 1997;32(9):920-4.
11. Whitehead WE, Palsson OS, Feld AD, Levy RL, Von Korff M, Turner MJ, et al. Utility of red flag symptom exclusions in the diagnosis of irritable bowel syndrome. Alimentary Pharmacology & Therapeutics. 2006;24(1):137-46.
12. Gwee K-A. Fiber, FODMAPs, flora, flatulence, and the functional bowel disorders. Journal of Gastroenterology & Hepatology. 2010;25(8):1335-6.
FOLLOW Shar with Paul Cribb PhD.