Diet for Irritable Bowel Syndrome (IBS) – Characteristics, Guidelines, Meal Plan
Irritable bowel syndrome (IBS) is a digestive disorder whose exact causes remain unclear. It is a condition characterized by abdominal pain and irregular bowel movements, which can make daily life more difficult. However, the right nutritional approach can help ease unwanted symptoms. What diet is recommended for IBS? What to eat and what to avoid? What can a typical IBS-friendly meal plan look like?
Table of contents
Irritable bowel syndrome - what is it?
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder considered a functional gut-brain interaction disorder, meaning it involves irregularities in how the gut and brain communicate.
IBS is one of the most common digestive diseases, affecting up to 20% of the population. It occurs twice as often in women than in men, especially among women aged 20–50.
Causes of irritable bowel syndrome
In IBS, disturbances in gut function – such as slowed or accelerated intestinal transit and increased bowel sensitivity – can send pain signals from the abdomen to the brain. Because this connection works both ways, stress can also directly influence bowel activity.
Although the exact cause of IBS is not fully known, it is most often associated with:
- chronic stress,
- gut dysbiosis,
- intestinal infections,
- food intolerances,
- gut-brain axis disorders,
- abnormal intestinal motility,
- psychological factors, e.g., anxiety disorders,
- genetic predisposition.
The Western diet, high in rapidly fermentable short-chain carbohydrates and short-chain fatty acids, may also contribute to bloating and lower colon pH, which can trigger symptoms.
IBS - symptoms
IBS is a chronic condition with a recurring and remitting course. The most common symptoms include:
- abdominal pain that worsens after meals,
- abdominal discomfort,
- bloating,
- heartburn,
- nausea,
- excessive gas,
- irregular bowel habits – diarrhea, constipation, or alternating patterns.
Symptoms can occur simultaneously or alternate, and their severity and frequency can change over time.
IBS is currently diagnosed based on physical examination and symptom assessment using the Rome IV criteria. IBS is recognized when there has been recurrent abdominal pain for at least one day a week in the last three months, along with at least two of the following:
- pain related to defecation,
- pain associated with a change in stool frequency,
- pain linked to a change in stool consistency.
IBS - the FODMAP diet
IBS management often includes dietary adjustments to reduce symptoms and improve quality of life. The diet should be tailored to the patient’s specific symptoms.
The most commonly recommended approach is the low FODMAP diet (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) – an elimination diet that limits foods containing these fermentable carbohydrates, which can aggravate symptoms. Once symptoms improve, these foods are gradually reintroduced while monitoring the body’s response.
The low FODMAP diet is especially helpful for IBS with diarrhea and is typically followed for 6–8 weeks.
IBS diet - what to eat
The low FODMAP protocol allows:
- meat, seafood, eggs,
- dairy products – hard cheeses (cheddar, camembert), lactose-free milk, oat, rice, or almond milk,
- fruits such as raspberries, kiwi, oranges, blueberries,
- vegetables such as potatoes, carrots, cucumbers, tomatoes, peppers, celery,
- gluten-free grain products based on spelt, rice, or oat flour,
- butter, margarine, nut butter,
- dark chocolate, maple syrup, white sugar,
- fish and tofu.
IBS - what not to eat
On a low FODMAP diet, the following should be avoided:
- dry legumes such as chickpeas, soy, lentils,
- dairy products such as cottage cheese, cow’s milk, cream, soy milk, mascarpone,
- vegetables like onion, leek, garlic, broccoli, cauliflower, cabbage, beets,
- fruits like apples, watermelon, pears, plums, dried fruit, and canned fruit,
- wheat and rye grain products,
- honey, sweeteners like mannitol, sorbitol, xylitol, agave syrup, high-fructose corn syrup.
IBS - NICE guidelines
Alongside the FODMAP diet, people with IBS may follow the NICE guidelines (National Institute of Health and Care Excellence), which are easier to follow but can bring similar benefits.
The NICE recommendations suggest:
- eating regularly and without rushing, avoiding long gaps between meals,
- drinking at least eight glasses of fluids daily, preferably water or herbal tea (limit coffee and black tea to three cups a day),
- reducing alcohol and carbonated drinks,
- limiting resistant starch, often found in processed foods,
- avoiding fatty and fried foods,
- avoiding onion, cabbage family vegetables, and dry legumes,
- avoiding sweeteners,
- replacing wheat products with spelt-based alternatives,
- for bloating and gas, consuming oat products like oatmeal or oat flour,
- regularly eating flaxseed or psyllium husks.
NICE guidelines are less restrictive than the low FODMAP diet and may significantly improve quality of life, making them the first recommended approach before trying low FODMAP if symptoms persist.
IBS diet - recipes and sample meal plan
An IBS diet should always be personalized based on individual tolerance and preferences. Here is an example plan:
Breakfast - Oatmeal with blueberries and dark chocolate
Ingredients: 4 tbsp oats, 200 ml lactose-free milk, a handful of blueberries, 2 squares dark chocolate.
Preparation: Bring milk to a boil, add oats, and stir. Let it sit covered until thickened, then transfer to a bowl, add washed blueberries, grate the chocolate, and mix.
Second breakfast - Veggie-loaded sandwich
Ingredients: 1 slice 100% spelt bread, 1 tsp butter, lettuce leaf, handful of cherry tomatoes, 1/2 cucumber, slice of poultry ham, pinch of salt and pepper.
Preparation: Wash and dry vegetables. Spread butter on bread, add lettuce, ham, sliced cucumber, and cherry tomatoes. Season lightly.
Lunch - Chicken drumstick with white rice and carrot slaw
Ingredients: chicken drumstick, 50 g white rice, 2 carrots, 1/2 celery root, 1 tsp olive oil, favorite spices, 1 tbsp canola oil.
Preparation: Wash and season chicken, then bake at 200°C for about 1 hour. Cook rice according to package instructions. Wash, peel, and grate carrots and celery, drizzle with olive oil, and mix. Serve rice and chicken drizzled with canola oil.
Afternoon snack - Banana pancakes
Ingredients: 1 unripe banana, 5 tbsp light spelt flour, 1 egg, 1 tsp canola oil, pinch of cinnamon, 4 tbsp lactose-free yogurt, optional canola oil for frying.
Preparation: Mash banana in a bowl, add flour, egg, oil, and cinnamon, and mix until smooth. Cook on a dry pan or with a little oil, flipping after 2 minutes per side. Serve with lactose-free yogurt.
Dinner - Tuna salad
Ingredients: 300 g tuna in water, 1 red pepper, handful cherry tomatoes, 1 egg, 2 tbsp olive oil, favorite spices, 1 slice 100% spelt bread.
Preparation: Drain tuna, place in a large bowl. Boil egg until hard, peel, chop, and add to tuna. Wash and chop vegetables, add to the bowl, season, drizzle with olive oil, and mix. Serve with spelt bread.
IBS - supplementation
Following a proper diet and eating small, regular meals can reduce symptom frequency and improve daily comfort. In some cases, supplementation can help.
Testing for nutrient deficiencies is recommended, as IBS – especially diarrhea-predominant – can impair absorption. If deficiencies are found, vitamin or mineral supplements may be advised by a doctor.
Soluble fiber supplementation can be beneficial – found in fruits, vegetables, psyllium husks, and oat bran. Probiotics may also help, but should be chosen carefully, as the wrong strain can worsen symptoms.
Bibliography:
- https://pubmed.ncbi.nlm.nih.gov/28592442/
- https://pubmed.ncbi.nlm.nih.gov/34376515/
- https://pubmed.ncbi.nlm.nih.gov/33651094/
- https://pubmed.ncbi.nlm.nih.gov/35125827/
- https://www.nice.org.uk/guidance/cg61/chapter/Recommendations#dietary-and-lifestyle-advice
- https://ptg-e.org.pl/wp-content/uploads/2022/03/Wytyczne-IBS-pol-2018.pdf