Irritable bowel syndrome (IBS) refers to a disorder that involves abdominal pain and cramping, as well as changes in bowel movements.1
Rome II Diagnostic Criteria for IBS At least 12 weeks (which need not be consecutive) in the preceding 12 months of abdominal discomfort or pain with two of the following features:
- The abdominal discomfort or pain is relieved with defecation and/or 2
- the onset is associated with a change in frequency of stools and/or 2
- the onset associated with a change in the form (appearance) of stool 2
Symptoms that cumulatively support the diagnosis of IBS:
- Abnormal stool frequency (perhaps more than 3 bowel movements per day or less than 3 bowel movements per week) 2
- Abnormal stool form (lumpy/hard or loose/watery) 2
- Abnormal stool passage (straining, urgency, feeling of incomplete evacuation) 2
- Passage of mucus 2
- Bloating or feeling of abdominal distension 2
Two Main IBS Categories
Irritable Bowel Syndrome (IBS) can be subdivided into two major categories.
1. Constipation-Predominant (IBS-C)
- Symptoms tend to alternate between constipation and normal stools. 2
- Symptoms of lower abdominal cramping or aching or discomfort are commonly triggered by eating. 2
2. Diarrhoea-Predominant (IBS-D)
- The person may tend to experience diarrhoea early in the morning or after eating. 2
- The need to void the bowel is typically urgent, and cannot be delayed. 2
- There may also be an incontinence problem. 2
Studies have estimated that the prevalence of irritable bowel syndrome at 10-20% and the incidence of irritable bowel syndrome at 1-2% per year. 2 Of people with IBS, approximately 10-20% will seek medical care. 2 An estimated 20-50% of gastroenterology referrals relate to this symptom complex. 2 In Western countries women are 2-3 times more likely to develop IBS than men but are also more likely to seek medical intervention. 2 Approximately 50% of people with irritable bowel syndrome report symptoms beginning before they were aged 35 years. 2
The exact cause of irritable bowel syndrome is poorly defined however it is avidly being researched. There are a number of hypotheses as to aetiologies of IBS, these include: altered colonic transit, bacterial infections of the enteric lining of the bowel, changes in neurohormonal mechanisms in relation to stress and dietary irritants such as lactose or fructose intolerance and poor absorption of short chain fats. 2-6
Health Impact – How the condition affects other Systems
At present there is no clear evidence that has been established linking IBS with inflammatory bowel diseases such as Crohn’s disease, ulcerative colitis or even bowel cancer. 7 What has been established is that psychological stress is a prominent underlying component of irritable bowel syndrome and there is a strong correlation between anxiety and depression amongst people with IBS. 7 It is not entirely clear how stress, anxiety and irritable bowel syndrome are related, or which one comes first, but studies show they tend to co-exist. 7
Therapeutic Considerations and Protocol
- Address major psychological issues (refer to psychologist/ counselor where appropriate) 3-5
- Address food sensitivities and allergies (avoidance of known triggers and foods that are highly processed and high in sugar; elimination diet, refer to Australian Biologics for food testing, herbs & supplements that restore/repair GI function & motility) 3-5
- Support digestion (pancreatic enzymes, carminatives, bitter herbs & foods) 3-5
- Address constipation (promote high fibre diet/hypo-allergenic diet) 3-5
- Address candidiasis if suspected (anti-candidia diet, probiotics such as saccharomyces boulardii, herbs that are anti-fungal) 3-5
- Address dysbiosis (Lactobacillus, Bifidbacterium, saccharomyces boulardii) 3-5
- Reduce colon spasm (peppermint oil, anti-spasmodic herbs, magnesium) 3-5
- Improve stress management (exercise, relaxation techniques) 3-5
Avoidance of Short-Chain Carbohydrates
It has been reported that those with IBS that avoid short-chain carbohydrates such as lactose and fructose often report an improvement in abdominal symptoms. 8 It is thought that this may be due to the difficulty with the absorption of the short-chain carbohydrates that in turn produce excessive amounts of hydrogen and carbon dioxide at a rate much faster than the body is able to metabolise. 3,5 This results in abdominal distension and symptoms such as abdominal pain, gas and bloating. 3,5 A study that used hydrogen breath testing to diagnose fructose malabsorption in those with IBS later examined the effects of dietary restriction of such short-chain carbohydrates. The study revealed that of the 62 patients with IBS or fructose malabsorption, there was a 74% total reduction in abdominal symptoms (of a total of 77% of patients that adhered to the diet). 8
Avoidance of Trigger Foods
It has been established that some foods make symptoms if IBS worse. These foods include: sugar, alcohol, coffee, chocolate, excessively fatty foods, brassica vegetables, legumes, beans, onions, wheat and corn. 3-5, 9 It is generally recommended that patients suffering IBS use a food diary to help single out trigger foods. Some practitioners will recommend food allergy testing such as IgG4 testing to identify food triggers. 4
Studies have found that all types of IBS respond to some form of exclusion diet; 9 In a definitive study, 200 of 253 patients were able to complete 2 weeks on an exclusion diet and 100 (50%) were successful in controlling their symptoms. 9
Gas symptoms may be relieved by reducing the intake of beans, cabbage, lentils, legumes, apples, grapes, raisins and sugar-free/artificial sweeteners such as sorbitol, xylitol, or mannitol. 5
Meals that are high in refined sugar contribute to IBS and small intestinal bacterial overgrowth by decreasing intestinal motility. 4
A large cohort study that looked at lactose, fructose and sorbitol intolerance in patients with functional bowel disorders found that of the 239 patients, 94 met the diagnostic criteria for IBS, while the rest were categorized as having functional complaints.10 Using hydrogen and methane testing, 90% of the subjects were found to suffer from some type of intolerance, with a large portion of patients exhibiting intolerance to more than one type of sugar. 10 With dietary restriction, approximately half of the subjects in each group experienced significant symptom improvement. 10
Adding more insoluble fibre (commonly found in whole grains) help to create firm, bulky stools. It normalizes digestion and may help to relieve symptoms of IBS such as, constipation, diarrhoea, abdominal pain, and bloating. Good sources of dietary fibre include whole grains (breads, cereals, whole grain pastas, brown rice, quinoa, and buckwheat), most vegetables and fruit, and legumes (such as dried peas, beans, lentils). 5
Concentrated fibre sources such as products containing Psyllium seed and linseed (provide 4-6 g of fibre when mixed with 250ml water) are natural fibres containing mucilages and are bulking agents with lubrication properties. These may be obtained in a supplement form and added to the diet to increase dietary fibre intake. It is recommended that those with IBS consume 20 to 35 grams of fibre a day to facilitate colonic motor function. 5
Those with IBS need to drink between 2-3L of water daily to ensure adequate hydration of the bowel in those with IBS-D and to ensure healthy bowel motility and those with IBS-C. 3, 4, 5
Probiotics may be obtained both in the diet and through supplementation. Foods that are good sources of probiotics include fermented foods such as yoghurt, kim chi, miso, kumbucha and sauerkraut. 5 Probiotics also come is a wide range of dietary supplement formulations from powders to enteric-coated capsules and tablets. The most specific probiotic strains for IBS management include the Lactobacillus strain plantarum, and the strains Lactobacillius acidophilus and Bifidobacterium. 3-5
The herbs passionflower, peppermint, chammomile, lemon balm and hops are considered beneficial for the symptomatic relief of minor gastrointestinal problems (such as indigestion, spasms and cramping) when these symptoms are related to worry, nervousness, tension and irritability. 4,5 Substitute coffee with any of the above teas and and drink between 3-4 cups per day or more if required.
Table (a) 9
|Foods to Avoid||Foods Allowed|
|Beef||All other meat and poultry|
|Fish in batter or breadcrumbs||White/fatty fish tinned in brine/oils eg sunflower, soya, olive|
|Potatoes, onions, sweetcorn, tinned vegetables in sauce||All other vegetables fresh/frozen/canned|
|Citrus fruits, tomatoes & tomato products, canned & dried fruit||All other fruits fresh|
|Wheat, rye, oats, barley, corn||Rice, arrowroot, tapioca, sago, millet, buckwheat, soya flour, psyllium, chia seeds, flaxseeds, beans, lentils, peas|
|Dairy products, sheep/ goats milk, eggs||Soya milk, milk-free margarine, rice milk, almond milk, oat milk|
|Tea, coffee, alcohol, citrus fruit juices/squashes, tap water||Herbal teas, other fruit juices, blackcurrant squash, mineral water|
|Yeast, gravy mixes, marmalade, salad cream/dressings, blended oils, corn oils||Salt, herbs, spices, olive oil|
|Vinegar, nuts, chocolate, all confectionary, artificial flavourings/colourings/sweeteners||Seeds, carob, honey/fructose (in minute amounts), stevia|
A recent meta-analysis of randomised, controlled trials reported that probiotic use is associated with improvements in global IBS symptoms and reductions in abdominal pain compared to placebo. The probiotic strains that have been clinically proven to be the most beneficial include Lactobacillus fermentum PCC 11,12 L. plantarum 299V 13,14 and the probioitc strains contained within the probiotic supplement known as ‘VSL #3’ (Lactobacillus casei, L. plantarum, L. acidophilus, and L. delbrueckii subsp. Bugariscus, Bifidobacterium longum, B. breve and B. infantis, and Streptococcus salvivarius subsp. Thermphilus, B. infantis L plantarum)
Studies have proven the probiotic Lactobacillus strain plantarum to have beneficial effect for patients with IBS, including improvements in stool frequency and abdominal pain. 14
Other Probiotics such as Lactobacillius acidophilus and Bifidobacterium may prove helpful in certain cases of IBS. 15
Each brand will have slight variations in amounts of colonising live organisms per dose, for example, Ethical Nutrients IBS Support formula contains 20 billion of L. plantarum 299V per capsule, whilst the brand Totally Natural Products: Nourishing flora only contains 1.66 billion of L. plantarum 299V per capsule. It is therefore recommended that when selecting a probiotic to look for the one with the highest quantity of L. plantarum 299V per capsule in order to have a strong therapeutic effect.
A minimum of 1 to 2 billion live organisms of Lactobacillus acidophilus is recommended daily. 4
Plantago spp (Psyllium):
The conclusion which can be drawn from the trials on Plantago (psyllium) seeds of husks is that, while these preparations significantly improve constipation, there is little evidence that they improve pain and other symptoms of IBS, 15-18 other than having a regulatory action in diarrhoea. 19
A double-blind crossover trial on 18 patients found that peppermint oil significantly improved well-being and reduced abdominal symptoms in IBS patients. 19
Another trial involving 29 patients acquired similar results. 20
The enteric-coated peppermint oil capsules used in both trials contained 0.2mL of oil and the dosage was 2 capsules 2 to 3 times daily. 19,20 Enteric-coating capsules are generally recommended as this ensures that the capsules do not dissolve in the stomach and prevents against oesophageal reflux.
L-tryptophan & 5-HTTP:
The amino acid L-tryptophan or its associated derivative, 5-hydroxytryptophan (5-HTP), may be recommended as part of treatment of IBS due to the existing relationship with serotonin, a neurotransmitter that is produced in both the digestive system and the brain. As there is a strong correlation between anxiety and depression amongst people with IBS, it is thought that by supporting the serotonin pathway with supplementation of L-tryptophan and 5-HTP, this may help to combat such emotional states and in turn make symptoms associated with stress more manageable. 21
- Regular exercise helps the body to cope with stress and anxiety by stimulating the brain to release endorphins, which promote a “feel good” response.
- Incorporate stress management techniques such as meditation and relaxation may aid the management of IBS symptoms. Referral to a counseller or psychiatrist may be recommended in some cases depending on severity of anxiety or depression.
- Maintain adequate hydration: Drink 6-8 glasses of water each day. Water is essential for combatting constipation and replaces the extra fluid lost if diarrhoea is a factor. Patients with diarrhoea may also benefit from an electrolyte replacement formula to decrease the risk of dehydration.
- Keep a symptom diary to assist in pinpointing any foods that trigger IBS symptoms. Avoid any foods that may be identified as being triggers of IBS symptoms. Common food intolerances to consider include dairy and grains (such as wheat) as well as stimulants such as caffeine.
- Supplement with fibre: Fibre supplements are more likely to be of benefit if you experience constipation than if you experience diarrhoea. It is common for symptoms such as bloating to temporarily worsen until your body gets used to the increased fibre, and it is therefore recommended to introduce fibre slowly and also increase your water intake as you increase your fibre.
- Avoid sugary foods, which may interfere with the balance of bacteria in the intestinal tract and slow down peristalsis.
- Slippery elm powder has traditionally been used to soothe irritated or inflamed mucous membranes of the digestive tract, and may help to relieve pain and promote healing. However, it may interfere with the absorption of other medicines; separate doses by two hours.
- Sit down to eat and chew foods slowly. Taking the time to chew meals properly means that the digestive processes have already started before the food arrives into the stomach, and also gives the stomach adequate time to prepare for the food's arrival by producing the enzymes and gastric juices needed for its digestion.
(1) Innes JA 2009, Davidson’s Essentials of Medicine, Elsevier: China.
(2) The Merck Manuel Library Online: Rome Criteria for irritable bowel syndrome; Available online at: http://www.merckmanuals.com/professional/sec02/ch022/ch022a.html (Last updated September 2007) Accessed August 2011.
(3) Sarris J & Wardle J 2010, Clinical Naturopathy, Elsevier: Chatswood.
(4) Pizzorno J & Murray M, 2008, The Clinicians Handbook of Natural Medicine, Elsevier Ltd: USA.
(5) Jamison, J, 2003. Clinical Guide to Nutrition & Dietary Supplements in Disease Management, Churchill Livingston: Australia.
(6) Osiecki H 2001, The Physicians Handbook of Clinical Nutrition, Bioconcepts Publishing: Eagle Farm.
(7) Shaw, A. D. Davies, G. J. & Dickerson, J. W. T. Irritable colon — Psychological aspects; Journal of Nutritional & Environmental Medicine, Dec97, Vol. 7 Issue 4, p307-318; , 12p
(8) Shepherd SJ, Gibson PR. Fructose malabsorption and symptoms of irritable bowel syndrome: guidelines for effective dietary management. J Am Diet Assoc 2006; 106: 1631-9.
(9) Daley J. Managing a rotation diet . J Comp Med 2008; 7:26-30
(10) Nucera, G et al Abnormal breath tests to lactose, fructose and sorbitol in irritable bowel syndrome may be explained by small intestinal bacterial overgrowth; Alimentary Pharmacology & Therapeutics 2005 21:1391-1395
(11) Conway PL, et al. Modulation of faecal enteric bactria and symptoms of irritable bowel syndrome using Lactobacillus fermentum and resistant starch. J Diet Suppl 2005: In press.
(12) Amansec S et.al Lactobacillus fermentum PCC relieves the symptoms of medically diagnosed irritable bowel syndrome. Unpublished 2005
(13) Nobaek S. et al. Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome. Am J. Gastroenterol 2000;95(5):1231-1238
(14) Niedzielin K, et al. A controlled , double-blind, randomised study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome. Eur J Gastroenterol Hepatol 201;13:1143-1147
(15) Duffy LC, Leavens A, Griffiths E, et al: Perspectives on Bifidobacteria as a biotherapeutic agents in gastrointestinal health, Dig Dis Sci 44;1499-505, 1999)
(16) Longstreth, G Fet al: Ann Intern Med 95, 53 (1981)
(17) Prior, A and Whorwell, P J: Gut 28, 1510 (1987)
(18) Kumar, A et al: Gut 28, 150 (1987)
(19) Jalihal, A and Kurian, G: J Gastroenterol Hepatol 5, 507 (1990)
(20) Soifer, L O et al: Acta Gastroenterol Latinoam 17, 317 (1987)
(21) Agazzi A, De Ponti F, De Giorgio R, et al Review of the implications of dietary tryptophan intake in patients with irritable bowel syndrome and psychiatric disorders Dig Liver Dis 2003;35:590-595
(22) Metagenics: Australian Practitioner Product Guide (Healthworld Ltd Publications) QLD; Dec 2009