Gut health

The Perfect IBS Diet

The perfect IBS diet? If you’ve had gut problems going on for a long time – perhaps the doctor has told you that you have irritable bowel syndrome (IBS) – you will likely have been trying to work out whether you can control the difficult symptoms through diet. You may have come across many different suggestions as to what you should eat. Sometimes some diet changes seem to work, other times everything you eat appears to make things worse. Let’s get some clarity!

What is IBS?

Irritable bowel syndrome is a term for a collection of bowel symptoms that cannot be attributed to other causes. The typical symptoms are: Pain that usually comes and goes and feels crampy and often is relieved by going to the toilet. Change in bowel habit (constipation, diarrhoea or fluctuation between the two). Stools may become small and pellet-like perhaps with signs of mucus. Bloating (although not all doctors include bloating), often accompanied by gas. You will usually have to have experienced these symptoms at least once a week for more than 6 months to be given a diagnosis of IBS.

What causes IBS?

Because a diagnosis of IBS is based on symptoms, getting a diagnosis does not explain what the causes may be. However, we know that it can often develop after a gut infection,1,2 such as Campylobacter, and it is associated with a change in the composition of the gut bacteria (dysbiosis).3,4 As well as imbalances in gut bacteria, people with IBS may also have “leaky gut”,5-10 changes in the hormones that control how fast food moves through the intestines, how much digestive enzyme they secrete,11 and may have some kind of intolerance to certain specific foods.12

How can diet help IBS?

Changing your diet can help improve the balance of your gut bacteria, influence the hormones that control the digestive process, encourage digestive enzyme production and remove foods to which you are intolerant: all of this can dramatically help symptoms. Given that over 80% of IBS sufferers report worsening of symptoms with some foods,13,14 looking at changing how you eat is certainly worth considering. Unfortunately, the scientific studies are not able to agree on what that diet should be.13 This is likely because the specific factors affecting an individual will vary from person to person. This does not mean that it is not possible to find the perfect diet for YOU. You just need to know how to go about it! Get practical tips on how to formulate the perfect IBS diet for you, here.

  1. Halvorson HA, Schlett CD, Riddle MS, Al-Haddad M. Postinfectious irritable bowel syndrome - A meta-analysis. Am J Gastroenterol. 2006;101(8):1894-1899. doi:10.1111/j.1572-0241.2006.00654.x
  2. Simrén M, Öhman L. Pathogenesis of IBS: Role of inflammation, immunity and neuroimmune interactions. Nat Rev Gastroenterol Hepatol. 2010;7(3):163-173. doi:10.1038/nrgastro.2010.4
  3. Mayer EA, Savidge T, Shulman RJ. Brain-gut microbiome interactions and functional bowel disorders. Gastroenterology. 2014;146(6):1500-1512. doi:10.1053/j.gastro.2014.02.037
  4. Chey W, Menees S. The gut microbiome and irritable bowel syndrome. F1000Research. 2018;7. doi:10.12688/f1000research.14592.1
  5. Gecse K, Róka R, Séra T, et al. Leaky gut in patients with diarrhea-predominant irritable bowel syndrome and inactive ulcerative colitis. Digestion. 2012;85(1):40-46. doi:10.1159/000333083
  6. Fasano A, Sapone A, Zevallos V, Schuppan D. Nonceliac gluten sensitivity. Gastroenterology. 2015;148(6):1195-1204. doi:10.1053/j.gastro.2014.12.049
  7. Brown BI. Does Irritable bowel syndrome exist? Identifiable and treatable causes of associated symptoms suggest it may not. Gastrointest Disord. 2019;1(3):314-340. doi:10.3390/gidisord1030027
  8. Fukui H. Increased intestinal permeability and decreased barrier function: does it really influence the risk of inflammation? Inflamm Intest Dis. 2016;1(3):135-145. doi:10.1159/000447252
  9. Dunlop SP, Hebden J, Campbell E, et al. Abnormal intestinal permeability in subgroups of diarrhea-predominant irritable bowel syndromes. Am J Gastroenterol. 2006;101(6):1288-1294. doi:10.1111/j.1572-0241.2006.00672.x
  10. Camilleri M, Lasch K, Zhou W. Irritable Bowel Syndrome: Methods, Mechanisms, and Pathophysiology. The confluence of increased permeability, inflammation, and pain in irritable bowel syndrome. Am J Physiol Liver Physiol. 2012;303(7):G775-G785. doi:10.1152/ajpgi.00155.2012
  11. Leeds JS, Hopper AD, Sidhu R, et al. Some patients with irritable bowel syndrome may have exocrine pancreatic insufficiency. Clin Gastroenterol Hepatol. 2010;8(5):433-438. doi:10.1016/j.cgh.2009.09.032
  12. Cuomo R, Andreozzi P, Zito FP, Passananti V, De Carlo G, Sarnelli G. Irritable bowel syndrome and food interaction. World J Gastroenterol. 2014;20(27):8837-8845. doi:10.3748/wjg.v20.i27.8837
  13. Rej A, Aziz I, Tornblom H, Sanders DS, Simrén M. The role of diet in irritable bowel syndrome: implications for dietary advice. J Intern Med. 2019;286(5):490-502. doi:10.1111/joim.12966
  14. Werlang ME, Palmer WC, Lacy BE. Irritable bowel syndrome and dietary interventions. Gastroenterol Hepatol. 2019;15(1):16-26.

Caroline Rees
Caroline Rees

Caroline is a a Registered Nutritional Therapist and member of the British Association for Nutrition and Lifestyle Medicine. She holds a master's level postgraduate diploma in Nutritional Therapy and a PhD in Immunology.