Unlock Relief: The Ultimate High-Fiber Diet Guide for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that affects a significant portion of the adult population worldwide. Characterized by symptoms like abdominal pain or cramping, gas, bloating, constipation, and diarrhea, IBS can significantly impact one's quality of life. While the exact cause of IBS remains unclear, it's believed to be related to issues with how the brain and intestines work together. Dietary changes, particularly those involving fiber intake, are often recommended to manage IBS symptoms.

Understanding Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder with a prevalence of 10-20% among the adult population worldwide. The diagnosis of IBS is based mainly on symptom assessment using the Rome criteria. The cardinal symptom is abdominal discomfort/pain, which is associated with altered bowel habits and abdominal bloating/distension. Patients with IBS are divided into four subtypes according to the stool pattern: diarrhea-predominant IBS (IBS-D), constipation-predominant IBS (IBS-C), mixed-diarrhea-and-constipation IBS (IBS-M) and unclassified IBS. Patients with IBS are usually diagnosed at a young age, and IBS is more common in women than in men.

The Role of Dietary Fiber in Managing IBS

Dietary fiber, comprising non-digestible carbohydrates and lignin found in plants, plays a crucial role in managing IBS symptoms. It has long been used in the treatment of several gastrointestinal conditions. While it's widely believed that IBS is caused primarily by a deficient intake of dietary fiber, research suggests a more nuanced relationship. Increasing dietary fiber intake has been the standard recommendation for patients with IBS. However, a systematic meta-analysis based on 12 small studies showed that increased dietary fiber consumption by patients with IBS did not improve IBS symptoms compared to placebo or a low-fiber diet. Other studies have shown that while consuming water-insoluble fiber does not improve IBS symptoms, consuming soluble fiber improves overall IBS symptoms. Subsequent studies have shone new light on fiber supplementation as a treatment for IBS. Several comprehensive reviews have been published recently on the role of dietary fibers in IBS.

If you have irritable bowel syndrome, too much or too little dietary fiber can affect symptoms. Most doctors recommend increasing dietary fiber intake to relieve symptoms, but some types of fiber may be better tolerated than others. Dietary fiber is the part of plant foods that your body can’t digest or break down. There are two types of fiber, soluble and insoluble, and you may need to be cautious with how much of both you eat. Eating too much fiber might also affect your symptoms. Fiber comes from plants and is an essential part of a healthy diet. It aids digestion by bulking up your stool. Both soluble and insoluble fiber can be good options for IBS. But they act differently as they pass through your digestive system. Many foods contain both types. In general, fiber is found in plant foods like: fruits, vegetables, legumes, nuts, grains.

Soluble vs. Insoluble Fiber

Different types of dietary fiber are characterized by marked differences in physical and chemical structure, with the health benefits of dietary fiber being specific to each fiber type. Dietary fiber can be divided into soluble types (i.e., dissolving in water) and insoluble types based on their physical and chemical properties. Soluble dietary fiber can be subdivided into viscous (gel forming) and non-viscous. Dietary fiber can be divided further into short-chain and long-chain carbohydrates, and fermentable or non-fermentable types.

Read also: High-Fiber Diet for Better Health

Soluble Fiber: This type of fiber dissolves in water, forming a gel-like consistency in the gut. It can be helpful for people with both IBS-D (diarrhea-predominant) and IBS-C (constipation-predominant). Soluble fiber gets its name because it dissolves in water. Once dissolved, it forms a gel-like consistency in the gut. It can be helpful for people with IBS-D (with diarrhea) and IBS-C (with constipation). Foods rich in soluble fiber include legumes like black beans, lentils, and peas; vegetables like zucchini, pumpkin, Brussels sprouts, broccoli, carrots, and sweet potato; fruits like apples, oranges, berries, and figs; whole grains like brown rice, oats, and barley.
Insoluble Fiber: This type doesn't dissolve in water. It helps bulk up the stool, which can keep it moving through your digestive system and prevent constipation. Insoluble fiber may be recommended for people with IBS-C. But eating too much of it may lead to excess gas production that can cause bloating and abdominal pain. Foods containing insoluble fiber include whole grains like whole wheat flour and wheat bran; nuts and seeds like almonds and flax seeds; fruits like bananas and apples; vegetables like cauliflower, green beans, and potatoes. Research suggests this type of fiber may worsen symptoms in people with diarrhea-predominant IBS, and it could cause more pain, diarrhea, gas, and bloating.

Fermentable vs. Non-Fermentable Fiber

Fiber can also be broken down into fermentable and unfermentable. Fermentable fiber is more easily and quickly broken down by gut bacteria than nonfermentable fiber. As it’s digested, fermentable fiber, like pectin and fructo-oligosaccharides, produces gas and other byproducts that can cause issues in some people with IBS.

Fermentable Fiber: Highly fermentable dietary fiber can lead to increased production of gas in the gut, causing bloating, abdominal pain, and flatulence. In general, people with IBS will want to avoid foods high in fermentable fiber, also known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). Foods high in fermentable fiber include garlic, onion, beans, rye, and certain fruits and vegetables. Short-chain, soluble and highly fermentable dietary fiber (e.g., oligosaccharides) results in rapid gas production that can outpace the capacity of the gastrointestinal tract to absorb gas into the bloodstream for final elimination through the lungs. This imbalance can cause abdominal pain/discomfort, abdominal bloating/distension and flatulence.
Non-Fermentable Fiber: Foods containing moderately or low fermentable fiber don’t cause an excess of gas in the gut and are typically well tolerated by people with IBS. Foods like potatoes, brown rice, oats, and nuts such as almonds can provide soluble and nonfermentable fiber. On the other hand, long-chain, intermediate viscous, soluble and moderately fermentable dietary fiber (e.g., psyllium) results in a low gas production and the absence of the symptoms related to excessive gas production.

Read also: Delicious High-Fiber Smoothie Recipes

Recommended Fiber Intake for IBS

Doctors recommend increasing fiber intake by 22 to 34 grams (g) per day to help regulate your stools. But most adults in the United States and Canada consume an average of only 17 g of dietary fiber daily. The recommended daily intake varies based on age and sex:

Females ages 50 years and under: 25 to 28 g per day
Males ages 50 years and under: 31 to 34 g per day
Females ages 51 years and older: 22 g per day
Males ages 51 years and older: 28 g per day

Fiber Supplementation: Psyllium

If you’re not able to get enough fiber in your diet, supplements containing psyllium have also been shown to be an effective way to improve IBS symptoms. Psyllium comes from the seed of the plant called Plantago ovata. It contains soluble fiber that is nonfermentable. Physicians (particularly those in the primary care system) usually recommend patients with IBS to increase their intake of dietary fiber to 20-35 g daily in order to regulate the stools and reduce abdominal pain and meteorism. Supplementation with long-chain, intermediate viscous, soluble and moderately fermentable dietary fiber such as psyllium improves the global symptoms of IBS.

Speak with a medical professional before taking any supplements. If you do begin taking fiber supplements, start slowly, so your body can get used to them. Taking too much at once can lead to side effects, like gas and bloating. Be sure to increase your water intake if you take a fiber supplement, too.

The Low-FODMAP Diet and IBS

Most people with IBS report that certain foods trigger or worsen their symptoms. On top of eating more fiber, your doctor may suggest that you follow a low FODMAP diet. FODMAP foods are difficult for your intestines to digest and often lead to increased bloating and diarrhea. The low FODMAP diet is often used in the dietary management of irritable bowel syndrome (IBS). Whilst the diet can be an incredibly effective short term strategy for IBS if implemented correctly, it is also not uncommon for people to struggle consuming adequate fibre whilst following the elimination phase of the diet.

FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. Essentially these are all short chain sugars or carbohydrates which are found in many foods naturally but also can be added to foods during processing. These carbohydrates as the name suggests are fermented by the bacteria in our large bowel and they are a substrate for our gut microbes. The low FODMAP diet is a diet used under dietetic guidance for the management of IBS by initially restricting these fermentable sugars or carbohydrates to restrict the amount of substrate available for fermentation by the bacteria. The problem is that the fermentation of these sugars and carbohydrates is actually a beneficial process and helps us to develop a thriving gut microbiome. The low-FODMAP diet temporarily restricts these carbohydrates in order to relieve uncomfortable symptoms and give your digestive system a rest. Removing irritants gives your gut lining a chance to repair itself and can help restore a healthy balance of gut flora. If your symptoms improve, you can use the low-FODMAP diet to figure out which foods to limit in the future.

Additionally, your doctor may recommend an elimination diet to understand which foods trigger your symptoms. Some people with IBS avoid gluten, a protein found in wheat, barley, and rye; or lactose, a sugar found in cow’s milk, but research suggests there’s no clear evidence regarding their effectiveness.

What are FODMAPs?

FODMAPs are:

Fermentable: These are all foods that your gut bacteria feed on, converting them to gasses in a chemical process called fermentation.
Oligosaccharides: These are soluble plant fibers known as prebiotics, which feed the beneficial bacteria in your gut. Oligosaccharides include onions, garlic, beans/lentils and many wheat products. Sensitivity to oligosaccharides may help explain some cases of non-celiac gluten sensitivity. Since gluten-free grains are lower in fermentable sugars than grains that have gluten, some people who think they are sensitive to gluten may actually be sensitive to the oligosaccharides residing in wheat products.
Disaccharides: Lactose is the fermentable sugar in this group, the sugar in dairy and breast milk. Lactose intolerance is one of the most common food intolerances worldwide.
Monosaccharides: Fructose, the sugar in fruit, is the fermentable sugar in this group. But only in certain quantities and proportions, so not all fruits are affected.
Polyols: These are sugar alcohols, commonly used as artificial sweeteners. They are also found naturally in some fruits.

Why are FODMAPs difficult to digest?

FODMAPs are fermentable short-chain carbohydrates. Translated, that means two things: They are sugar molecules that are linked together in chains, and they are fermentable by the bacteria in your gut. Molecules in chains need to be broken down into single molecules to be absorbed through your small intestine. But FODMAPs can’t be broken down, so they can’t be absorbed there. Your small intestine draws in extra water to help move the FODMAPs through to your large intestine. There, the bacteria living in your colon have a field day fermenting them (eating them). This produces gasses and fatty acids as byproducts inside your gut.

Who might benefit from a low-FODMAP diet plan?

The low-FODMAP diet is often prescribed for limited periods for people diagnosed with irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO). Studies show that a majority of people living with these conditions benefit from the diet. It can also be used as a short-term elimination diet for anyone who has digestive problems and wants to try and isolate the foods that are causing them. An elimination diet removes common problem foods and then adds them back in systematically to observe how your system reacts. The low-FODMAP diet is just one of many elimination diets that you can use to discover food sensitivities.

What does a low-FODMAP diet consist of?

The diet has three phases: an elimination phase, a reintroduction phase and a maintenance phase that’s customized to you. During the elimination phase, you'll avoid all of the high-FODMAP foods - a list of specific fruits, vegetables, dairy products and grains. At first glance, the elimination phase of the diet may seem very limited. But there’s still a good list of foods in each category that you can eat. It takes some mental discipline to follow, but you won’t go hungry on the diet. After two to four weeks, you’ll begin the reintroduction phase, in which you systematically add foods back in. The third phase keeps what works for you and leaves out what doesn’t.

Practical Ways to Incorporate Fiber into Your Diet

Here are some practical ways to incorporate fiber into your daily nutritional intake:

Ensure You’re Getting Enough Soluble Fiber: Prioritize foods high in soluble fiber, such as oranges, apples, pears, blueberries, strawberries, peas, sweet potatoes, avocados, oats, turnips, carrots, bran, beans, and barley. However, moderation is key, and those with IBS-C should avoid excessive consumption of soluble fiber.
Be Careful When Consuming Insoluble Fiber: Insoluble fiber is often recommended for IBS-C patients dealing with constipation. Foods containing insoluble fiber include zucchini, broccoli, leafy greens, and cabbage. However, those with diarrhea and similar symptoms could have their IBS symptoms significantly worsened by a diet rich in insoluble fiber.
Supplement Your Fiber With Psyllium: Fiber supplements, namely psyllium, can provide a gentle laxative effect due to their soluble fiber content. However, they should not replace whole foods rich in fiber and should be used cautiously to avoid adverse GI symptoms.
Avoid High-FODMAP Soluble Fibers: Since specific types of short-chain soluble fibers (known as FODMAPS) often ferment when digested, they can cause bloating and gas. Avoiding these foods can help stave off IBS symptoms, but it’s typically suggested as a short-term strategy.
Prioritize Low-FODMAP Soluble Fiber: Long-chain soluble fibers low in FODMAPs, like chia and flax seeds, may help alleviate aggressive IBS symptoms. Potatoes, green beans, canned chickpeas, Brussels sprouts, sweet potatoes, zucchini, and summer squash are also low enough in FODMAPs to consume when following this diet.
Embrace the Power of Potatoes: As a low-FODMAP menu item, potatoes are highly nutritious and contain soluble and insoluble fiber, making them a well-rounded choice for those with IBS-C and IBS-D. However, they are high in carbohydrates and have a high glycemic index.
Consider Okra: Okra contains soluble and insoluble fibers and is packed with various nutrients. However, it is high in fructans, which can trigger IBS symptoms in certain situations.
Bolster Your IBS-Friendly Nutrition With Avocados: Avocados contain soluble fiber and can be easily integrated into many foods. However, they contain sorbitol, which is known to trigger IBS-related symptoms. Avocado oil may be a more friendly alternative for IBS patients.
Eat Blueberries: Blueberries are a fruit that’s friendly to IBS due to their low FODMAP nature. They can calm your GI system during a flare-up of irritable bowel syndrome.
Include Bananas: Bananas are affordable, easily accessible, and high in soluble fiber. However, bananas increase in FODMAP levels the riper they get.

Other Dietary Considerations

On top of eating more fiber, your doctor may suggest that you follow a low FODMAP diet. Additionally, your doctor may recommend an elimination diet to understand which foods trigger your symptoms.

Avoiding certain trigger foods may help with your symptoms. These foods can vary from person to person, but common triggers include: dairy, fried food, high fat foods, fizzy drinks, alcohol, caffeine, processed foods, foods containing insoluble fiber. The best foods for IBS are those rich in soluble fiber and low in FODMAPs, as well as those with healthy fats, and lean sources of protein. Examples include: lean meats, leafy greens, eggs, fish, nuts and seeds, certain fruits and vegetables.

When to Seek Medical Advice

Speak with a doctor if you’re experiencing IBS symptoms frequently, such as bloating, abdominal pain, diarrhea, and constipation. If you’ve already received an IBS diagnosis, see your doctor if your symptoms don’t improve after making changes to your diet, such as adding more fiber. They may refer you to a dietitian specializing in IBS and other gastrointestinal disorders. Treatment for IBS involves a combination of medications, dietary changes, and stress reduction.

tags: #high #fibre #diet #for #irritable #bowel