Irritable bowel syndrome ( IBS ), also known as irritable bowel, is a disorder characterized by abdominal pain and swelling, which is associated with impaired bowel motility. In fact, IBS patients may suffer from constipation or diarrhea or alternate both symptoms. Therapy is generally of a medical nature. However, in most patients, certain foods can trigger or worsen symptoms. In this article, we will therefore deal with the diet for irritable bowel and swollen bellies.
Irritable colon and swollen belly: FODMAP diet
The FODMAP diet was proposed in 2005 by Dr. Peter Gibson of Monash University as a possible treatment for irritable bowel syndrome. Over the years it has found a growing consensus in the medical community for the management of IBS symptoms and. Above all, for the reduction of abdominal swelling. The FODMAP diet, in fact, has been shown to reduce irritable bowel symptoms in at least 75% of patients, becoming the first-line therapy in the treatment of IBS 1 – 2. Plus its documented ability to reduce bloating by 50-80% makes it one of the best diets for a bloated belly 3.
FODMAPs are a particular group of short-chain carbohydrates (sugars), which are difficult to absorb from the intestine. On the one hand, in fact, they retain water, increasing the intestinal volume of liquids and, on the other hand, they ferment in the colon, favoring the formation of gas. Their consumption can therefore accentuate bloating, diarrhea, and stomach pain in patients with IBS. The diet for irritable bowel and swollen bellies. Therefore, provides for the reduction of the consumption of foods with high FODMAP content.
In particular, the acronym FODMAP indicates the following fermentable carbohydrates (F) :
- oligosaccharides (fructo-oligosaccharides / fructans and galacto-saccharides);
- disaccharides (lactose);
- monosaccharides (fructose);
- polyols (sorbitol, xylitol, and mannitol).
FODMAP diet: what to avoid
The FODMAP diet involves limiting the consumption of a long list of foods. Some of the main foods to avoid in case of irritable bowel and swollen stomach are:
- some types of fruit such as peaches, watermelon, pears, figs, mangoes, apples, plums, honey, and their derivatives ;
legumes such as beans, lentils, and chickpeas;
- cereals such as wheat, spelled, barley, rye and their derivatives (bread, pasta, etc.);
- some vegetables such as artichokes, cauliflower, mushrooms, garlic, onions, asparagus, sauerkraut, beets, leeks, broccoli (only the stem, because it is rich in fructose), Brussels sprouts, cabbage, green beans, pumpkins, leeks, radicchio, shallots, Jerusalem artichokes, cabbage;
- milk and derivatives such as dairy products, ice cream, and yogurt due to their presence of lactose;
- sweeteners such as xylitol, sorbitol, and mannitol are present, for example, in some candies and products for diabetics.
It should be noted that the list of cereals to be eliminated for their fructooligosaccharide content coincides with that of cereals containing gluten. However, the latter is not a FODMAP carbohydrate at all, but a protein complex. This means that if the elimination of these cereals were to improve gastrointestinal symptoms. It is necessary to make further tests to exclude the presence of celiac disease or, on the contrary, to confirm sensitivity to fructans. Some people, in fact, may be convinced that they are celiac when they are sensitive to fructans, and others. On the other hand, maybe celiac when the cause of their problems is actually the fructooligosaccharides.
The FODMAP diet only eliminates fruits, vegetables, and dairy products that have a high content of short-chain carbohydrates, while allowing the consumption of those that have a reduced amount. Low-FODMAP foods you can eat are:
- fruits such as bananas, berries (excluding blackberries), melon, grapefruit, kiwi, mandarin, lemon, mandarin, orange, and pineapple;
- products based on cereals and wheat-free derivatives, such as those without gluten. Some options are rice, oats, buckwheat, quinoa, and amaranth;
- Vegetables such as broccoli (discarding the stem), carrots, cucumbers, spring onions, chives, courgettes, eggplant, tomatoes, turnips, celery, spinach, and chili
- lactose-free milk such as rice, soy, kefir, and almond milk;
- lactose-free dairy products such as butter, very aged cheeses (parmesan and parmesan), and other lactose-free cheeses such as gorgonzola, fontina, and pecorino;
- meat, fish, shellfish, eggs;
- sugar in small quantities.
Remember that the FODMAP diet should be used as an elimination diet, during which FODMAPs are eliminated for a limited time (2-6 weeks), and then gradually reintroduced. This should allow you to find out which of the FODMAPs is responsible for the swollen belly. Thus narrowing down the list of foods to avoid. A protracted and generalized limitation of FODMAPs can in fact lead to nutritional deficiencies of fiber, calcium, iron, folate, and B vitamins, as well as possible alterations of the intestinal microbiome, such as a lack of butyrate and a decrease in bifidobacteria. For this reason, it is advisable to consult a nutritionist before starting the FODMAP diet.
The elimination diet, as its name suggests, involves eliminating certain foods for a certain period of time, in order to see if IBS symptoms improve. It can involve an entire class of nutrients, such as in the FODMAP diet. Or individual foods that are believed to trigger irritable bowel symptoms.
Some of the foods that commonly accentuate IBS symptoms are:
- some types of fruits and vegetables;
- foods and industrial products with artificial sweeteners.
In this case, the diet involves the elimination of one of these foods, or any food that is thought to be the cause of gastrointestinal disorders, for a period of 4 weeks. If the symptoms do not improve, the food is reintroduced and new food is eliminated to evaluate its impact on irritable bowel symptoms.
Diet and fiber
A diet for irritable bowel and a swollen belly cannot fail to consider the role of fibers. In fact, they can be friends or enemies of IBS symptoms depending on their properties.
First of all, it is necessary to distinguish between soluble and insoluble fibers. The former, mainly contained in fruit, beans, and oats, dissolve in water, while the latter, mainly present in cereals and vegetables, do not have this property.
If you suffer from irritable bowel, it is necessary to evaluate the specific symptoms of IBS. In fact, if you suffer from constipation, that is, you are suffering from an IBS with dominant constipation (IBS-C), the consumption of insoluble fiber can be useful. They increase the mass of stool, accelerating its transit and favoring its evacuation. However, if constipation, as is often the case, is accompanied by abdominal bloating, insoluble fibers must be avoided, as they can make it worse. In addition, most of the insoluble fibers derived from cereals, such as wheat bran, are rich in FODMAPs and have been found to be ineffective for irritable bowel 4.
What fibers for the irritable bowel?
The possible increase in swelling due to the consumption of insoluble fiber should not lead to limiting the general consumption of fiber. In fact, they can improve the symptoms of IBS and help prevent its onset 5. The recommendation is therefore to move towards soluble fibers which, thanks to their ability to dissolve in water, do not increase the mass of the stool, avoiding exacerbating abdominal swelling. It can also be useful, although not immediate, to identify natural sources of soluble fiber among low-FODMAP foods. So as to avoid the negative effects of short-chain carbohydrates, without giving up the benefits of fiber. Some possible options can be:
Finally, it should be noted that, regardless of solubility, the more fermentable fibers favor the production of gas, a symptom of IBS. In this regard, some studies 6 have suggested that psyllium fibers, soluble and with a low fermentation rate, are well tolerated and improve irritable bowel symptoms, even in the subtype with dominant constipation. However, further studies are needed to investigate their effectiveness.
Gluten is a protein found in grain-based products such as bread and pasta, which can cause celiac disease or non-celiac gluten sensitivity. In the latter case, it has been noted that some people sensitive to gluten are also affected by irritable bowel. For this reason, it has been hypothesized that the gluten-free diet may also be helpful in patients with IBS.
In a small 2016 study 7 of 41 people found that following a gluten-free diet for 6 weeks reduced IBS symptoms. Those who continued to follow the diet for 18 months also continued to have a reduction in symptoms.
A gluten-free diet involves the elimination of cereals (rye, barley, wheat) and their derivatives such as:
- bread and baked goods;
- breakfast cereals;
- cous cous;
- wheat germ;
A gluten-free diet involves the elimination of many foods. However, there are currently many gluten-free replacement products available.
Generally, patients suffering from irritable bowel tend to associate the appearance of their symptoms with the consumption of fatty foods 8. A low-fat diet is therefore often recommended for IBS 9. In fact, some laboratory studies have shown that fats in the duodenum reduce the motility of the small intestine. And alter the ability to eliminate intestinal gas, causing swelling 10. However, the evidence supporting the efficacy of a low-fat diet for IBS is limited and needs further investigation.
It should also be noted that some interesting studies 42 – 43 have instead suggested a positive effect of dietary fats in irritable bowel syndrome. Polyunsaturated fatty acids, of which the best known are omega 3 , can in fact reduce low-grade intestinal inflammation, which has recently been detected as a mechanism involved in IBS. The integration of polyunsaturated fatty acids in irritable bowel syndrome, therefore, deserves further study.