IBS diet: what to eat and what to avoid?

Irritable bowel syndrome (IBS) is a functional digestive disorder characterised by abdominal pain, bloating and changes in bowel movements - diarrhoea, constipation or alternation of both. As no underlying organ dysfunction can be detected, one of the most important pillars of treatment is an appropriate diet. Many people are unsure about what they can and should avoid eating if they have IBS. This guide will help you understand the basic principles of the IBS diet and provide practical advice on how to put together a diet to reduce discomfort and improve your quality of life.

The role of diet is key, as some foods can trigger or aggravate symptoms, while others can help to alleviate them. All IBS patients are advised to attend dietetic advice, as personalisation of diet is essential for effective symptom management. A good diet can not only improve physical well-being but also reduce the anxiety caused by the disease.

In this article, we detail the food groups that often cause complaints and those that are generally well tolerated. We also cover the importance of fibre intake, the FODMAP diet and other useful lifestyle tips that can contribute to a symptom-free everyday life. The aim is to give you an overview of how you can develop your own diet to meet your individual needs.

What exactly is IBS?

Irritable bowel syndrome is a condition characterised by chronic abdominal pain or discomfort associated with changes in bowel movements, without any underlying organ disease. Symptoms are often triggered by food or stress and may be relieved by defecation or passing of wind.

There are several subtypes of IBS based on the dominant symptom:

• Diarrhoea dominant (IBS-D): Patients often experience loose, watery stools after meals or in stressful situations.
• Constipation predominant (IBS-C): It is characterised by hard, berry-like stools, difficult and infrequent bowel movements and a feeling of incomplete emptying.
• Mixed type (IBS-M): In this case, periods of diarrhoea and constipation alternate.

To make an accurate diagnosis, a specialist gastroenterological examination is essential to rule out other diseases with similar symptoms (e.g. inflammatory bowel disease, celiac disease). The Endomedix gastroenterology centres, experienced specialists can help you make an accurate diagnosis and develop an appropriate treatment plan.

Basic principles of diet for IBS

The IBS diet aims to identify and avoid foods that trigger symptoms, while providing the nutrients the body needs. There is no one perfect IBS diet for everyone; the key is personalisation.

The role of fibres: soluble vs. insoluble

There are two main types of fibre and their effects on IBS symptoms can vary.

• Soluble fibres: They dissolve in water to form a gel-like substance that slows digestion. This can help relieve diarrhoeal symptoms and may also help constipation by improving the consistency of stools. Good sources include oats, barley, psyllium, carrots, apples and citrus fruits. Consumption of soluble fibre is generally recommended to relieve general symptoms of IBS and abdominal pain. It is important to start with a low dose (3-4 grams per day) and gradually increase the dose to avoid bloating.
• Insoluble fibres: They are insoluble in water and increase the bulk of the stool, stimulating bowel movements. Although this can be helpful in preventing constipation, for many IBS patients it can aggravate bloating, gas and abdominal pain. Examples of such fibres include wheat bran, whole grains and nut shells. Insoluble fibres, especially wheat bran, should be avoided.

The importance of the FODMAP diet

The FODMAP diet is one of the most effective, scientifically proven dietary interventions for the treatment of IBS symptoms. FODMAP is an acronym for fermentable oligo-, di-, monosaccharides and polyols. These are short-chain carbohydrates that are osmotically active (attract water into the gut) and are rapidly fermented by gut bacteria, which can lead to gas formation, bloating, abdominal pain and diarrhoea in susceptible individuals.

The FODMAP diet consists of three stages:

• Elimination phase (6-8 weeks): Elimination of all high FODMAP foods from the diet.
• Feedback phase: Gradual, one-by-one reintroduction of foods belonging to each FODMAP group to find out which type and how much the patient is sensitive to.
• A personalised diet: Based on experience, a diet that is sustainable over the long term and tailored to individual tolerance.

A dietitian is recommended to help you follow the diet properly, as strict restriction can lead to nutrient deficiencies. From Endomedix dietetic advice available at the centres will help you to follow the FODMAP diet safely and effectively.

What should we avoid? High FODMAP foods

The list below includes foods that often cause symptoms due to their high FODMAP content. These should be avoided, especially during the elimination phase of the diet.

• Vegetables: Onion, garlic, leek, artichokes, beetroot, cauliflower, mushrooms, asparagus, peas, cabbage.
• Fruits: Apple, pear, mango, cherry, watermelon, apricot, peach, plum, dried fruit.
• Cereals: Wheat, rye, barley (and products made from them, such as bread, pasta, pastries).
• Dairy products: Cow's milk, yoghurt, ice cream, soft cheeses (due to their high lactose content).
• They are thin: Beans, lentils, chickpeas.
• Nuts and seeds: Cashew nuts, pistachios.
• Sweeteners: Honey, high fructose corn syrup, and polyols (sugar alcohols) such as sorbitol, mannitol, xylitol (often in chewing gum, diet products).

What to eat? Low FODMAP foods

The following foods are generally well tolerated and safe to eat in the IBS diet.

• Vegetables: Carrots, cucumbers, tomatoes, courgettes, aubergines, peppers, spinach, salad vegetables, potatoes, green beans.
• Fruits: Bananas (unripe), oranges, mandarins, strawberries, blueberries, raspberries, kiwi, grapes.
• Cereals: Gluten-free grains such as rice, maize, quinoa, millet, oats (guaranteed gluten-free). A gluten-free diet alone is not recommended in IBS unless celiac disease is present, but wheat, rye and barley should be avoided due to their FODMAP content.
• Dairy products: Lactose-free milk, yoghurt and hard cheeses (e.g. cheddar, parmesan), plant milks (e.g. almond milk, rice milk).
• Protein sources: Meat, fish, eggs, tofu (firm).
• Nuts and seeds: Peanuts, walnuts, almonds (small amounts), pumpkin seeds, sunflower seeds.
• Sweeteners: Maple syrup, granulated sugar (small quantities).

More useful lifestyle advice

In addition to diet, other factors can also affect IBS symptoms.

• Regular meals: Eat smaller portions several times a day. Large, fatty meals can make symptoms worse.
• Adequate fluid intake: Drink enough water (2 litres a day). This is especially important in case of constipation. Avoid fizzy, sugary drinks and alcohol.
• Eat slowly: Eat slowly and chew your food thoroughly to aid digestion and reduce the air swallowing that can lead to bloating.
• Stress management: Stress has been shown to worsen the symptoms of IBS. Try relaxation techniques such as yoga, meditation or regular exercise.
• Exercise: Regular, moderate-intensity exercise can help regulate bowel function and reduce stress.

Expert help on the road

The IBS diet can be complex and challenging in the early stages. Proper diagnosis and personalised dietary guidance are essential for successful management of symptoms. Do not embark on a strict elimination diet without medical or dietitian supervision, as this can lead to nutrient deficiencies and complicate subsequent diagnosis.

If you experience symptoms suggestive of IBS, the first step is a thorough gastroenterological examination. Visit Endomedix private clinics with modern diagnostic equipment and highly qualified specialists to provide you with an accurate diagnosis. Our dietitians will then help you to develop a personalised diet that relieves your symptoms and is sustainable in the long term, contributing to a better quality of life.

Remember, IBS is a treatable condition and with the right diet and lifestyle, significant improvements can be made. Take the first step towards a symptom-free life and get help from our experts.