Vegan Diet: Friend Or Foe To Irritable Bowel?

Irritable Bowel Syndrome (IBS) is a chronic condition that affects the large intestine, causing symptoms that range from mild to debilitating. IBS is a functional bowel disorder, meaning the problem isn't with the structure of the bowels but with how they work. Diagnosis is made using the Rome criteria, which includes abdominal pain and discomfort lasting at least one day a week for the last three months, related to defecation, a change in bowel movement frequency, and/or a change in stool consistency. Other symptoms include bloating, gas, and straining. The exact cause of IBS is unknown, but it is rooted in a disturbance in the interaction between the gut, brain, and nervous system. Two of the biggest factors behind IBS are gut dysbiosis, an imbalance of bacteria in the GI tract, and stress and anxiety.

A vegan diet may appeal to those with IBS due to its health, ethical, or environmental benefits. However, there is no evidence that a vegan diet will decrease IBS symptoms, and for some people, it could make them worse as it can increase the intake of fermentable carbohydrates (FODMAPs). FODMAPs are found in dairy products and certain grains, vegetables, and fruits, and are poorly absorbed in the intestines, leading to water retention and gas formation.

The low FODMAP diet has been found to reduce IBS symptoms in up to 70% of people with IBS and involves three phases: a FODMAP reduction phase, a re-introduction phase, and a long-term modified diet. This diet can be done safely alongside a vegan diet with the right support and advice from a dietitian. A FODMAP 'gentle' approach may be easier and less restrictive, involving the removal of only a few very high FODMAP foods.

A well-balanced vegan diet includes proteins from nuts, seeds, and legumes, many of which can trigger IBS symptoms because they are difficult to digest. However, there are many plant-based foods that are free of these elements and are easier on the digestive system, such as rice, firm tofu, ginger, and spinach.

IBS is a chronic condition that affects the large intestine, causing symptoms that range from mild to debilitating

Irritable bowel syndrome (IBS) is a chronic condition that affects the large intestine, causing symptoms that range from mild to debilitating. It is a functional bowel disorder, meaning the problem is not with the structure of the bowels but with how they work. IBS is not diagnosed through testing such as blood tests, X-rays, or endoscopy, but rather through a set of diagnostic criteria called the Rome criteria. According to the Rome criteria, to be diagnosed with IBS, a patient should have abdominal pain and discomfort lasting on average at least one day a week for the last three months. This pain or discomfort should be related to defecation, associated with a change in bowel movement frequency, and/or associated with a change in stool consistency. Other symptoms of IBS can include bloating, gas, passage of mucus, straining, urgency, or a feeling of incomplete evacuation.

The exact cause of IBS is unknown, but it is believed to stem from a disturbance in the interaction between the gut, brain, and nervous system. People with IBS have unusually sensitive nerve endings in the GI system and are prone to feeling more intense pain at lower thresholds. Two of the biggest factors behind IBS are gut dysbiosis, an imbalance of the bacteria in the GI tract, and stress and anxiety.

While there are well-known health benefits of a plant-based diet, there is no evidence that increasing your intake of plant-based foods will decrease IBS symptoms, and for some people, it could make them worse. This is because a plant-based diet can increase the intake of fermentable carbohydrates (FODMAPs). However, increasing your intake of plant-based foods can promote good bacteria in your gut, so if you can tolerate an increase of these foods, it could be beneficial.

The low FODMAP diet has been found to reduce IBS symptoms in up to 70% of those with IBS. This diet has three phases: a FODMAP reduction phase, a re-introduction phase to identify trigger foods, and a long-term modified diet that avoids the trigger foods personal to you. The restriction phase restricts a number of foods, including wheat, high-lactose dairy foods, certain fruits and vegetables, onions, and garlic. However, there are plenty of foods that you can eat while following the diet, and any restricted foods should be replaced by suitable alternatives. For example, an apple could be swapped for an orange.

A plant-based diet can already be restrictive if not well-planned, and a vegan diet, especially, can lead to vitamin B12, iodine, calcium, and omega-3 deficiencies. Doing the low FODMAP diet on top of this could lead to social restrictions and nutritional deficiencies. Both diets can, however, be done together safely with the right support and advice, and a dietitian can help ensure that it is done in a nutritionally balanced way.

IBS is a functional bowel disorder, meaning there is a problem with how the bowels work, not their structure

Irritable bowel syndrome (IBS) is a chronic condition that affects the large intestine, causing symptoms that range from mild to debilitating. It is considered a functional bowel disorder, meaning there is a problem with how the bowels work, not their structure. Diagnosis is made using a well-accepted set of diagnostic criteria called the Rome criteria. According to the Rome criteria, to be diagnosed with IBS, a patient should have abdominal pain and discomfort lasting on average at least one day a week for the last three months. The pain or discomfort should be related to defecation, associated with a change in frequency of bowel movements, and/or associated with a change in stool consistency. Other symptoms of IBS can include bloating, gas, passage of mucus, straining, urgency, or a feeling of incomplete evacuation.

The exact cause of IBS is not known, though we know at the root is a disturbance in the interaction between the gut, brain, and nervous system. Two of the biggest factors behind IBS are gut dysbiosis, an imbalance of the bacteria in the GI tract, and stress and anxiety. Studies show that people with IBS have unusually sensitive nerve endings in the GI system and are prone to feeling more intense pain at lower thresholds. This can lead symptoms to flare up in conditions—dealing with a stressful situation or even simply eating a meal—that would not trigger symptoms in those without IBS.

It is often recommended for people to try a diet low in certain carbohydrates called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). FODMAPs are found in dairy products and certain grains, vegetables, and fruits. However, since so many healthy plant foods fall into the FODMAP category, totally cutting them out—while it may reduce symptoms in the short term—will lower the number of healthy microbes in the gut, increase the number of unhealthy ones, and leave you worse off in the long term.

A whole-food, plant-based diet improves the gut microbiome, which can improve IBS symptoms. Studies show that compared with people eating an animal-based diet, a plant-based diet increases microbiota diversity in part because it provides more fiber. Fiber is considered a first-line therapy in treatment recommendations for patients with IBS, according to the 2021 American College of Gastroenterology clinical guidelines. A 2018 study found that the more fiber participants consumed, the less likely they were to have IBS. Soluble fiber—found beans, oats, lentils, and certain fruits—may serve as a prebiotic, feeding beneficial bacteria in the gut. Research suggests that insoluble fiber, the “roughage” that whole grains and vegetables tend to be rich in, has a laxative effect that can relieve constipation.

IBS is not diagnosed through testing but by a well-accepted set of diagnostic criteria called the Rome criteria

Irritable Bowel Syndrome (IBS) is a condition that affects the bowel and digestive tract. It is characterised by symptoms such as abdominal pain, bloating, diarrhoea and/or constipation, and excessive gas. IBS is relatively common, affecting 7-15% of the population, and is usually diagnosed before the age of 50.

IBS is not diagnosed through specific testing, but rather by a set of diagnostic criteria known as the Rome criteria. The Rome criteria is a well-accepted standard used by medical professionals to diagnose IBS. This is because there is no single test, such as a blood or stool test, that can be used to diagnose IBS. Instead, a doctor will ask about your symptoms, their frequency, duration, and any potential triggers, such as certain foods.

Before diagnosing IBS, other conditions will be ruled out through various tests. These include blood tests to check for coeliac disease, and tests on stool samples to check for infections and inflammatory bowel disease.

If you suspect you have IBS, it is important to consult a medical professional for a proper diagnosis. They will be able to assess your symptoms and provide guidance on the best course of treatment or dietary changes.

IBS symptoms can be triggered by certain foods, but also by the environment and stress

Irritable Bowel Syndrome (IBS) is a chronic condition that affects the large intestine, causing symptoms that range from mild to debilitating. It is considered a functional bowel disorder, which means the problem isn’t with the structure of the bowels; it’s with how they work. IBS is a relatively common condition, affecting between 7-15% of the population. It is more common among women and is usually diagnosed before the age of 50.

It is often recommended for people to try a diet low in certain carbohydrates called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). FODMAPs are found in dairy products and certain grains, vegetables, and fruits. However, since so many healthy plant foods fall into the FODMAP category, totally cutting them out—while it may reduce symptoms in the short term—will lower the number of healthy microbes in the gut, increase the number of unhealthy ones, and leave you worse off in the long term.

A whole-food, plant-based diet improves the gut microbiome, which can improve IBS symptoms. Studies show that compared with people eating an animal-based diet, a plant-based diet increases microbiota diversity in part because it provides more fiber. Fiber is considered a first-line therapy in treatment recommendations for patients with IBS, according to the 2021 American College of Gastroenterology clinical guidelines. A whole-food, plant-based diet that is rich in fiber helps to produce short chain fatty acids, which is the key to building a robust gut microbiome, says Dr. Sarina Pasricha, MD, MSCR, a gastroenterologist specializing in gut motility. Fiber adds bulk to stool, speeds up its transit through the colon, and can help regulate bowel movements. A 2018 study found that the more fiber participants consumed, the less likely they were to have IBS.

However, most people with IBS will need to go slowly when beginning a plant-based diet. It is important to not jump to conclusions, because foods aren’t the only triggers. “Patients with IBS may be able to eat one food item one day and not have an issue, but the exact same food item on a different day will create an issue,” says Dr. Sarina Pasricha, MD, MSCR, a gastroenterologist specializing in gut motility. “That’s where environment and stress play a role as triggers. It is always worth reintroducing and retrying foods to see if it’s the food or that environment—like eating too quickly that day—causing the issue.”

Dairy is a common trigger food for IBS

The low-FODMAP diet has been found to reduce IBS symptoms in up to 70% of people with IBS. This diet involves three phases: a FODMAP reduction phase, a re-introduction phase, and a long-term modified diet. The reduction phase restricts wheat, high-lactose dairy foods, certain fruits and vegetables, onions, and garlic. While dairy alternatives like soy milk are low-FODMAP, they are not always nutritionally adequate substitutes for dairy.

It is important to note that a vegan diet that restricts FODMAPs can lead to nutritional deficiencies, especially in vitamin B12, iodine, calcium, and omega-3. Therefore, it is recommended to work with a dietitian to ensure a nutritionally balanced diet. A FODMAP 'gentle' approach, which involves removing only a few very high FODMAP foods rather than all of them, may be a less restrictive option for those following a plant-based diet.

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