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Irritable Bowel Syndrome

Treatment options, current recommendations and guidelines Marianne Williams, NHS & Private Specialist Allergy & IBS Dietitian Web:; Twitter: @allergydiet

Irritable bowel syndrome (IBS) is a chronic and debilitating functional gastrointestinal disorder, which has a significant impact on quality of life.1 It is characterised by abdominal pain, bloating, change in bowel habit and with an absence of any overt mucosal abnormality. IBS is non-life threatening and its pathogenesis remains poorly understood.2-5

Background Many patients lack confidence in their IBS diagnosis, with 50% considering the diagnosis to be a ‘catch all’. The resulting uncertainty and anxiety leads inevitably to a demand for further tests, with patients concerned that their symptoms may develop into cancer, colitis or may shorten their life expectancy.6, 7 Additionally, despite National Institute for Health and Clinical Excellence (NICE) IBS recommendations in 2008 advising against referral for diagnostic tests, research suggests that general practitioners (GPs) still see IBS as a diagnosis of exclusion often due to a poor understanding of the condition and in the belief that negative diagnostic tests are useful.8-10 This is likely to explain why, despite current guidelines, the costs for treating IBS remain high. It is the commonest cause of referral to gastroenterologists in the developed world, with around half of IBS patients being referred for endoscopic investigation.3, 11 Indeed, research shows that IBS patients incur 51% more costs per year than a control group, with more outpatient visits and higher medications costs.12 As a result it forms a significant burden on the NHS in terms of demand on specialist services, with spending steadily increasing year-on-year, reaching a total attributable cost of almost ÂŁ12 million for 2012-2013.11

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Many patients report an exacerbation of symptoms after eating and this can lead to over restrictive diets and reinforce a vicious cycle of health worry, with increased GP visits and demands for more testing and prescriptions.6 Historically doctors have been unable, or unwilling, to offer specific dietary advice as there seemed to be limited evidence for its involvement in IBS.6 However, in the last decade there has been a dramatic increase in research investigating diet and its effect on IBS symptoms and a greater emphasis on the need for specialist dietetic intervention. The 2016 update of the British Dietetic Association dietary guidelines for IBS critically appraised all research up to October 2015, using the robust Practice-based Evidence in Nutrition (PEN) methodology, risk of bias assessments on all research papers and followed National Health and Medical Research Council (NHMRC) guidelines evidence statement matrices.13 The result was a valuable document for all those working in the field of IBS and nutrition. Fundamentally, there are now two avenues of treatment according to these new guidelines: first line looking at healthy eating/lifestyle, recognised dietary triggers for IBS and lactose intolerance; second line revolving around the low FODMAP (Fermentable, Oligo-, Di-, Mono-saccharides and Polyols) diet.

Irritable Bowel Syndrome | Big Story

First line advice Regular meal patterns, taking time over meals, chewing food thoroughly and not eating too late at night were all advocated. However, it was also recognised that in IBS it may be beneficial to look at fibre, alcohol, caffeine, spicy food, fat and fluid. There was some moderate quality evidence for fibre supplementation in IBS, but overall the studies looking specifically at these areas were often limited with a high risk of bias. Nevertheless, if a detailed case history is suggestive of an association with any of these factors then it is considered relevant to alter intakes appropriately. A trial period on a low lactose diet can be beneficial with some IBS patients, particularly in those with an ethnic background who may be more susceptible to lactase deficiency. However, it is important that the patient fully understands that a low lactose diet is not a ‘dairy-free’ diet: while a low lactose diet simply reduces the intake of dairy foods high in lactose – e.g. milk, manufactured yogurt, ice-cream – a dairy-free diet eliminates all sources of mammalian dairy and is only appropriate for those patients with suspected dairy allergy and is not suitable for IBS patients. Confusion about the difference is common amongst the public and the medical profession. This confusion is compounded by the fact that symptoms can be similar with bloating, wind, diarrhoea, constipation, nausea, abdominal pain often occurring in both conditions. This highlights the need for specialist dietetic input in order to differentiate and treat appropriately.14, 15

Second line advice Second line dietary intervention advice for IBS now revolves predominantly around the low FODMAP diet and there has been a surge in good quality randomised control trail (RCT) studies over recent years.16-20 This was reflected by NICE in 2015, who now suggest consideration of this diet where basic diet and lifestyle measures have been unsuccessful.4 The first meta-analysis of low FODMAP RCTs reported that the diet is likely to help abdominal pain, bloating and overall gastrointestinal (GI) symptoms, while a more recent meta-analysis of the diet confirmed significant improvements in gastrointestinal symptoms, abdominal pain and health-related quality of life. Research consistently shows that 50-80% of IBS patients report symptomatic benefit with the low FODMAP diet.21, 22 What is less clear is the longevity of response to this diet. Most research shows

short-term results over a number of weeks, but do symptoms continue to be improved once FODMAP reintroduction is complete? A recent long-term study looking at 103 patients showed that of the 63 patients who initially showed satisfactory relief, 70% maintained this improvement after 6-18 months. Interestingly, 82% of patients continued to follow an ‘adapted FODMAP diet’, with only 18% returning to their ‘habitual diet’. From a health economic perspective, it was notable that significantly more patients on the ‘adapted diet’ ceased medication in comparison to those on the habitual diet, although the adapted group had a greater use of supplements to support their diet. Nutritional adequacy of this diet has often been questioned,20 but

“Many patients report an exacerbation of symptoms after eating and this can lead to over restrictive diets and reinforce a vicious cycle of health worry, with increased GP visits and demands for more testing and prescriptions.6”

this study showed that there were no significant differences between the adapted and habitual group for energy or nutrient intakes, with the exception of folate and vitamin A which were ironically higher in the adapted group.23 From a negative perspective, the low FODMAP diet can have a significant effect on the colonic bacteria, although, presently most studies are simply descriptive observations. Indeed, the effect seems logical as this diet reduces the intake of prebiotics, such as fructans and galactooligosaccharides (GOS), which could potentially alter the composition and functioning of the GI microbiota.24 Three RCTs have shown a reduction in bifidobacterial, with one study showing a 47% reduction in total bacterial load. What remains unknown are the longterm effects of this diet on the bacterial community and how these changes may affect their metabolic output and whether this could have potential health consequences. Research is urgently needed to determine if the low FODMAP reintroduction process attenuates these changes. There is recent good quality RCT evidence suggesting that probiotic supplementation alongside the diet may be of benefit, but more research is needed before probiotics could be standardly recommended as an adjunct to the low FODMAP diet.17 The low FODMAP diet has been used with some success in inflammatory bowel disease, although, concern remains over whether the diet may be exacerbating bacterial changes already seen in this patient cohort.24, 25 Despite these concerns, Cox et al. recently undertook an RCT re-challenge study with a mixture of patients in remission from either UC or Crohn’s disease and with diagnosed functional gastrointestinal symptoms.

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Big Story | Irritable Bowel Syndrome

References: 1. Spiegal B (2009). The burden of IBS: Looking at Metrics. Current Gastroenterology Reports; 11: 265-9. 2. MaxionBergemann S TF, Abel F, Bergemann R (2006). Costs of irritable bowel syndrome in the UK and US. Pharmacoeconomics; 24(1): 21-37. 3. Parkes GC, Sanderson JD, Whelan K (2010). Treating irritable bowel syndrome with probiotics: the evidence. Proc Nutr Soc.; 69(2): 187-94. 4. National Institute for Health and Care Excellence (2015). Irritable bowel syndrome in adults: diagnosis and management of irritable bowel syndrome in primary care. CG61. Accessed online: (Aug 2017). 5. Drossman DA (2016). Functional Gastrointestinal Disorders: History, Pathophysiology, Clinical Features and Rome IV. Gastroenterology. 6. Halpert A, et al. (2007). What patients know about irritable bowel syndrome (IBS) and what they would like to know. National Survey on Patient Educational Needs in IBS and development and validation of the Patient Educational Needs Questionnaire (PEQ). Am J Gastroenterol; 102(9): 1972-82 7. Spiller R, Garsed K (2009). Postinfectious irritable bowel syndrome. Gastroenterology; 136(6): 1979-88. 8. National Institute for Health and Care Excellence (2008). Irritable Bowel Syndrome: Costing report implementing NICE guidance. CG61. Accessed online: www. (Aug 2017). 9. Bellini M TC, et al. (2005). The general practitioners approach to irritable bowel syndrome: From intention to practice. Digestive and Liver Disease; 37(12): 934-9. 10. Spiegel B (2010). Is irritable bowel syndrome a diagnosis of exclusion? A survey of primary care providers, gastroenterologists and IBS experts. Am J Gastroenterology; 105(4): 848-58. 11. Soubieres A, et al. (2015). Burden of irritable bowel syndrome in an increasingly cost-aware National Health Service. Frontline Gastroenterology; 0: 1-6. 12. Longstreth G (2003). Irritable bowel syndrome, health care use, and costs: a U.S. managed care perspective. Am J Gastroenterol; 98(3): 600-7. 13. McKenzie YA, et al. (2016). British Dietetic Association systematic review and evidence-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). J Hum Nutr Diet; 29(5): 549-75. 14. Fiocchi A (2010). World Allergy Organisation (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines. WAO Journal. 15. Holgate ST CM, Broide DH, Martinez FD (2012). Allergy. 4th Edition ed: Elsevier Saunders. 16. Halmos EP, et al. (2014). A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology; 146(1): 67-75 e5.. 17. Staudacher HM, et al. (2017). Diet Low in FODMAPs Reduces Symptoms in Patients with Irritable Bowel Syndrome and Probiotic Restores Bifidobacterium Species: a Randomized Controlled Trial. Gastroenterology; doi: 10.1053/j.gastro.2017.06.010. 18. McIntosh K, et al. (2016). FODMAPs alter symptoms and the metabolome of patients with IBS: a randomised controlled trial. Gut; 66(7): 1241-1251. 19. Hustoft TN, et al. (2017). Effects of varying dietary content of fermentable short-chain carbohydrates on symptoms, fecal microenvironment, and cytokine profiles in patients with irritable bowel syndrome. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society; 29(4). 20. Staudacher HM, et al. (2012). Fermentable carbohydrate restriction reduces luminal bifidobacteria and gastrointestinal symptoms in patients with irritable bowel syndrome. J Nutr.; 142(8): 1510-8. 21. Marsh A, Eslick EM, Eslick GD (2016). Does a diet low in FODMAPs reduce symptoms associated with functional gastrointestinal disorders? A comprehensive systematic review and meta-analysis. Eur J Nutr.; 55(3): 897-906. 22. Schumann D, et al (2017). Low FODMAP Diet in the Treatment of Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis. Nutrition; DOI: 23. O'Keeffe M, et al. (2017). Long-term impact of the low-FODMAP diet on gastrointestinal symptoms, dietary intake, patient acceptability, and healthcare utilization in irritable bowel syndrome. Neuro gastroenterology and motility; doi: 10.1111/nmo.13154. 24. Staudacher HM, Whelan K (2017). The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut; 66(8): 1517-27. 25. Prince AC, et al. (2016). Fermentable Carbohydrate Restriction (Low FODMAP Diet) in Clinical Practice Improves Functional Gastrointestinal Symptoms in Patients with Inflammatory Bowel Disease. Inflamm Bowel Dis.; 22(5): 1129-36. 26. Cox SR, et al. (2017). Fermentable carbohydrates (FODMAPs) exacerbate functional gastrointestinal symptoms in patients with inflammatory bowel disease: a randomised, double-blind, placebo-controlled, cross-over, re-challenge trial. J Crohns Colitis. 27. Williams M, et al. (2016). Using best practice to create a pathway to improve management of irritable bowel syndrome: aiming for timely diagnosis, effective treatment and equitable care. Frontline Gastroenterology; DOI: 28. Whigham L, , et al. (2015). Clinical effectiveness and economic costs of group versus one-to-one education for shortchain fermentable carbohydrate restriction (low FODMAP diet) in the management of irritable bowel syndrome. J Hum Nutr Diet.; 28(6): 687-96. 29. Williams M. Post IBS Webinar Survey - Survey Monkey. Personal Audit Data; 2017. 30. Gibson PR, Skodje GI, Lundin KE (2017). Non-coeliac gluten sensitivity. J Gastroenterol Hepatol.; 32(1): 86-9. 31. Uhde M, et al. (2016). Intestinal cell damage and systemic immune activation in individuals reporting sensitivity to wheat in the absence of coeliac disease. Gut; 65(12): 1930-7. 32. Carroccio A, et al. (2017). Persistence of Nonceliac Wheat Sensitivity, Based on Long-term Follow-up. Gastroenterology; 153(1): 56-8 e3. 33. Biesiekierski JR, et al. (2011). Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial. Am J Gastroenterol; 106(3): 508-14; quiz 15. 34. Biesiekierski JR, et al. (2013). No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology; 145(2): 320-8 e1-3. 35. Catassi C, et al. (2015). Diagnosis of Non-Celiac Gluten Sensitivity (NCGS): The Salerno Experts' Criteria. Nutrients; 7(6): 4966-77. 36. McKenzie YA, et al. (2016). British Dietetic Association systematic review of systematic reviews and evidence-based practice guidelines for the use of probiotics in the management of irritable bowel syndrome in adults (2016 update). J Hum Nutr Diet; 29(5): 576-92. 37. Fritscher-Ravens A, et al. (2014). Confocal endomicroscopy shows food-associated changes in the intestinal mucosa of patients with irritable bowel syndrome. Gastroenterology; 147(5): 1012-20. 38. Wouters MM, Vicario M, Santos J (2016). The role of mast cells in functional GI disorders. Gut; 65(1): 155-68. 39. Bischoff SC (2016). Mast cells in gastrointestinal disorders. Eur J Pharmacol; 778: 139-45.

The results showed that fructans induced GI symptoms, while GOS and sorbitol in the doses given did not induce symptoms. However, doses were given as drinks and it could be that if FODMAPs are consumed in a more realistic manner, where several FODMAPs are combined within foods throughout the day, that results may differ. More research is needed to determine the degree and type of FODMAP restriction necessary in IBD patients who suffer with IBS functional symptoms.26


IBS guidelines did not recommend a gluten-free diet for IBS. However, this is



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The overall success of the low FODMAP diet is compelling and despite concerns on the effects to gut bacteria, the diet is now considered an accepted part of IBS treatment in the UK.4, 13 This has inevitably led to increased demand on dietetic services and a need for specially trained dietitians. Work by the NHS community dietetic team in Somerset has led to the development of community based dietetic led gastroenterology services within the UK seeing patients on a one-to-one basis, while work by King’s College London has shown great success with FODMAP group sessions.27, looking


The Somerset team are now





which may represent a more practical method of treating large numbers of patients within a sizable rural county. Early data from these webinars shows that patients are finding them easy to use and that the webinars are improving patient education. Patients report that they are keen to join the evening sessions as they can gain reliable information from specialist dietitians without having to take time off work and can re-watch the session whenever they wish.29 The challenge now will be to collect long-term reliable data

a growing area of knowledge and is likely to be re-evaluated in future updates as new research becomes available.

Probiotics The use of probiotics in IBS was looked at in exceptional detail in this latest BDA IBS Guidelines with a systematic review of the systematic reviews involving 35 RCTs and a total of 3,406 patients. The fundamental findings were that probiotics are ‘unlikely to provide substantial benefit to IBS symptoms’, but that taking a probiotic was considered safe in IBS. However, individuals who wished to try a probiotic were not discouraged from doing so and were advised to try one product at a time for a minimum of four weeks at the manufacturers recommended dose and to monitor effects.36

Elimination diets Previous advice on specific ‘elimination diets’ from the original BDA IBS guidelines, in 2012, has been removed in the latest update. The simple reason for this change is that there is insufficient evidence that these diets are relevant in IBS. Elimination diets are used regularly within food allergy were the immune system is activated by proteins in the diet, but as yet there is no conclusive evidence that the immune system is involved specifically in IBS. Research into mast cell involvement in subsets of patients with IBS-type symptoms is ongoing. However, it remains to be elucidated if this immune involvement falls under the remit IBS, or whether these patients simply have similar symptoms with a differential diagnosis of food allergy.37-39


on this cohort showing effectiveness of the






Other dietary areas of interest in IBS Gluten-free diet There is heightened interest in a glutenfree diet in both the media and general population, but the current research linking gluten specifically to IBS symptoms remains controversial and conflicting.30-34 More research is needed in this area to differentiate the effects of gluten from other elements found in wheat, barley and rye, such amylase trypsin inhibitors (ATI’s) and the fermentable carbohydrates known as ‘fructans’.30, 35 As a result, the latest BDA

Fundamentally, after many years in the wilderness of knowledge, this last decade has finally led to the development of robust recommendations for the dietary treatment of IBS. This has put dietitians at the forefront of IBS care. It is acknowledged that more research is needed, particularly into the effects of the low FODMAP diet on gut microbiota and who would best benefit from dietary intervention. It is also acknowledged that restrictive diets may not be suitable for all IBS patients. However, for a condition that can have such a significant impact on quality of life, and that has historically been so difficult to treat, the new guidelines, research and use of innovative forms of dietetic-led patient communication can finally give realistic hope to many IBS patients.

2017 IBS Treatment Options, Recommendations & Guidelines  
2017 IBS Treatment Options, Recommendations & Guidelines