Our gastrointestinal tract is constantly exposed to internal and external influences such as environmental factors and nutrients through the food we eat, all of which control our gastrointestinal ecosystem. Although it is obvious that food therefore directly impacts the health of our gut, or the way it reacts to food depending on its state of health, this aspect is often overlooked. Our gut is the largest immune organ in our body, and our colon, which comprises only approximately 1.5 – 1.8 m of our gut, is one of the most densely packed microbial ecosystem on earth. This makes the gut highly complex, so that it both influences and is influenced by our overall health. Apart from its function as a protective barrier and an immune organ, it is responsible for digestion and absorption. We do not need to suffer from severe intestinal diseases such as Colitis ulcerosa or Morbus Crohn to make necessary adjustments to our nutrition. Simple discomforts such as bloating can also be regulated through the food we eat. Our nutrition appointments always consider gastrointestinal health as part of our standard procedure for personalized nutrition.
Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS) has become increasingly common among individuals who suffer from chronic abdominal pain and changes in bowel habits. IBS has been estimated to affect 11-12% of the population globally, and mostly women than men, with a common ratio of 2:1. However, individuals increasingly self-diagnose themselves with IBS when experiencing different kinds of abdominal discomfort, leading to high reports of IBS without a concrete diagnosis. Individuals must consult with a Gastroenterologist to make sure their symptoms are not caused by any other condition or disease, such a celiac disease. In order to be formally diagnosed with IBS, a set of tests must be performed to rule out other health problems which often mimic the symptoms and signs of IBS. Apart from a thorough medical and family history, these tests may include a physical exam, blood test, stool test for signs of infection or disease, hydrogen breath test for SIBO or intolerances, and finally an endoscopy to rule out colon cancer, inflammatory bowel disease or celiac disease. Equally important are psychological factors and stress, which have been shown to affect bowel function through the brain-gut axis.
Once other conditions and diseases which could cause similar symptoms have been ruled out, and once certain warning signs have been excluded as listed in Table. 1, a formal set of criteria, known as the Rome IV Criteria, has been developed for research and clinical care to confirm the suspected diagnosis of IBS.
The Rome IV Criteria for diagnosis of IBS state that there must be:
Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria:
1. Related to defecation
2. Associated with a change in frequency of stool
3. Associated with a change in form (appearance) of stool
(These criteria should be fulfilled for the last 3 months with symptom
onset at least 6 months prior to diagnosis).
Modified according to 'Microbiome: the link between brain and bowels', Journal of Physiology and Pharmacology
Table 1: IBS Exclusion Criteria
1. Age > 50 without prior colon cancer screening
2. Presence of overt GI bleeding
3. Nocturnal passage of stools
4. Unintentional weight loss
5. A family history of inflammatory or colorectal cancer
6. Recent changes in bowel habits
7. Presence of a palpable abdominal mass or lymphadenopathy
Lacy BE, Patel NK (2017). Rome Criteria and a Diagnostic Approach to Irritable Bowel Syndrome, Journal of Clinical Medicine 26;6(11).
Note that pain is an essential part of the diagnosis. If an individual fulfills the criteria and is therefore diagnosed with IBS, the IBS subtype must then be identified based on the abnormal bowel movements reported by the individual. There are three subtypes of IBS as can be seen in Table 2; IBS-C which describes predominant constipation, IBS-D which describes predominant diarrhea and IBS-M which describes mixed bowel habits. Constipation classifies as stool type 1 & 2 (hard or lumpy) based on the Bristol stool scale and diarrhea as stool type 6 & 7 (loose or watery). If an individual classifies for IBS based on the Rome IV Criteria but does not categorize into one of the three IBS-subtypes, this then falls into the category IBS-U (IBS-Unclassified).
Table 2: IBS Subtypes
Table 1 & 2 modified according to Lacy BE, Patel NK (2017). Rome Criteria and a Diagnostic Approach to Irritable Bowel Syndrome, Journal of Clinical Medicine 26;6(11).
(incl. when FODMAP elimination can help and when prolonged elimination can lead to worsening of symptoms)
As the prevalence in IBS rises, so do different dietary approaches and trends, the latest being the Low-FODMAP diet. Fodmaps are short chain carbohydrates, the name deriving from 'Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols'. Disaccharides include lactose and monosaccharides include fructose, sugars to which individuals can be intolerant to without suffering from IBS, i.e. without fulfilling the Rome IV Criteria. Since IBS can be multifaceted, it is not reasonable to stick to one approach or a particular IBS diet. IBS must be handled with an open mind, as results from research are based on statistics, meaning that although a large number of people react to certain trigger foods, this does not necessarily apply to everyone. The approach we take is based on a thorough diet history, from which we extract your symptoms, your IBS-type, further co-factors such as stress, and subsequently create an individualized elimination diet specifically tailored to you. An individualized elimination diet eliminates the triggers which we suspect are specifically relevant to you. This may be an elimination of a single food or a combination of different foods, i.e. only certain fodmap-containing foods accompanied with insoluble fibre. The options are endless as we do not usually follow a fixed elimination procedure. However, fodmaps are often used inappropriately as a standard diagnostic tool for IBS. In these cases, other underlying causes of your symptoms or diseases with similar symptoms, such as inflammatory bowel disease, can be overlooked. This is because anyone suffering from bowel symptoms can experience an improvement when eliminating fodmaps. In fact, a recent study has shown that eliminating unnecessary fodmaps for too long can potentially reduce beneficial gut bacteria, eventually increasing IBS pain and driving the sufferer to a vicious cycle (Hill P. et al., 2017). Fodmaps can be the root cause of IBS symptoms and their careful and selective elimination can indeed be beneficial, however, this must be implemented in the appropriate setting and with the guidance of a professional.
Hill P, Muir JG, Gibson PR (2017). Controversies and Recent Developments of the Low-FODMAP diet, Gastroenterology and Hepatology 13(1): 36–45.