Food building-blocks and Bloating with IBS

Changing the food we eat (i.e. diet) can have a huge impact on symptoms, whether it be Constipation, Diarrhoea or Bloating/gas and any associated tummy Pain or discomfort.

Remember diets for IBS:

• Are not weight-loss diets.

• Are not about eating lots of fibre - some is good, but too much fibre may make symptoms worse.

• Might not improve symptoms completely - other things can also be a cause of IBS symptoms e.g. a lot of stress, too much alcohol, certain medication.

Very important: The phrase "Healthy Diet" means nothing! In fact, many foods that we are encouraged to eat for "health" can make IBS worse!

The diets that we suggest for you will be the ones that are most likely to resolve your particular bowel symptoms.

Being consistent in following each Diet will be very important.

But, if we are to talk about Diet, first we need to talk about Food itself. Many factors can worsen gut symptoms and a really important one of these is Diet. Being informed about how different foods can cause symptoms, will help you understand why different diets are suggested for specific gut symptoms - this will help put you in control of your tummy.

20.1 The building-blocks of food
Food is made up of many micronutrients (vitamins and minerals) and other components that are present in relatively small amounts. Macronutrients are present in much larger amounts and could be described as the 'building blocks' of food:

• Carbohydrates

• Fats

• Fibre

• Proteins

You should never completely exclude any of these important building blocks, but restricting the amount or changing the type is key to improving diet-related symptoms.

20.1.1 Carbohydrates (Carbs)
These are often called the 'energy' foods and they include starch and sugars. Different carbohydrates are made up of chains or strings of different sugar units (glucose, fructose, galactose, etc) that mostly are digested (snipped apart) by enzyme molecules (like a chemical "scissors") present on the lining of our guts in the small bowel.

- Starch (e.g. as in bread, potato, pasta) is actually a 'string' of glucose sugar units (molecules) attached to each other like a pearl necklace i.e. each sugar unit is a 'pearl': Starch = glucose units attached to each other

Our guts can digest starch, because we have the enzyme to snip the glucose units from each other. But, it's a very different matter with other common carbohydrates called fructans and galactans - we don't have the enzyme to separate the sugar units, so we are not able to digest them and that's when the trouble can start.

- Fructans = fructose units attached to each another (mainly found in wheat, vegetables e.g. onion, garlic)

- Galactans = galactose units attached to each another (mainly found in peas, beans and lentils)

- Fructose = fructose units that are not joined together (mainly found in fruits)

20.1.2 How might carbohydrates be a problem in IBS
Not having enough of the enzyme to digest fructans or galactans means that these carbohydrates cannot be snipped apart in the small bowel and so end up in the large bowel where bacteria have the enzymes to ferment them. The products of fermentation by bacteria can cause problems:

20.1.3 Gas (hydrogen and methane) that can stretch the bowel causing discomfort or pain. Methane gas can 'paralyse' gut muscle, which it is thought can even cause constipation.

20.1.4 Fatty acids can irritate the bowel wall, having a laxative effect and causing loose / frequent stools.

Some diets (e.g. low-FODMAP) reduce the intake of foods high in fructans and galactans, which reduces the formation of products of fermentation that can cause excess gas, bloating, loose stools or indeed constipation.

20.2 Fats
Fat is made up of two basic types: saturated and unsaturated. At room temperature, saturated fat is solid e.g. butter and lard; but unsaturated fat is liquid e.g. olive oil, vegetable oil.

Weight-for-weight olive oil has the same number of calories as lard, but olive oil is good for the heart whereas lard is not. The same is true for other unsaturated and saturated fats.

Our body is unable to make certain fats (omega-3 fats and omega-6 fats) so we call these 'essential' fats, because we must obtain them from our diet. A certain amount of fat in our diet is good and is needed for good health.

For example, fat helps absorb fat soluble vitamins such as vitamin A, D, E and K. Fat is also an essential part of the walls of all our cells and helps nerves to communicate properly.

20.2.1 Healthy fats: Some foods are naturally high in fat e.g. nuts, seeds, avocado and they contain a large proportion of the type of fat (unsaturated) that is better for health.

20.2.2 Less healthy fats: There is a vast amount of food that contains 'less healthy' fat. For example, cakes, biscuits, pastries, pies, cheese, chocolate all contain a high proportion of fats (saturated) that potentially can harm our health.

20.2.3 How might fat be important in IBS: As far as our gut is concerned all fat types are simply 'fat', regardless of whether or not it is good for the heart. The enzyme that digests saturated fat is the same as the enzyme that digests unsaturated fat.

Fatty or oily foods tend to slow down the emptying of our stomachs and this is why we can feel very full, even nauseous (with belching or heartburn), after a 'rich' (meaning high in fat) meal.

Also, for some people, fatty or oily foods, once past the stomach, tend to rush through the gut and so worsen any IBS symptoms e.g. tummy cramping, diarrhoea.

Too much of any type of fat can cause tummy discomfort or other gut symptoms. Eating the amount of fat that your gut tolerates (i.e. is 'happy' with) is one of the aims of self-managing your gut symptoms.

20.3 Fibre
Fibre is important in managing IBS, but in different ways for different people - there is not "one rule for all". This could mean eating less or more of it. It is the part of plant foods that we are unable to digest, because we don't have the "scissors" (enzymes) to break it up.

Fibre therefore travels undigested through the Small bowel to the large bowel (Colon) where it is fermented by bacteria, which can be a major issue for those of us with IBS.

Nutrition health professionals say that fibre is good for health and generally, it is. Fibre is good for heart health and it plays an important role in the health of our gut. But, that is not to say that we can all tolerate the same amount of fibre in our diet.

20.3.1 Types of fibre
There are broadly two different types of fibre. Plant foods contain a mixture of both types, but some foods will contain more of one type than the other.

20.3.2 Soluble fibre: oats are the best known example of a food rich in soluble fibre - nuts, some fruits (and vegetables) are also a source.

20.3.3 Insoluble fibre: wheat bran is the best known example of insoluble fibre - corn, some fruits (and vegetables) are also sources.

20.3.4 Fibre and Fluid
Fibre absorbs fluid and expands into a type of 'jelly' in the bowel. This bulks out our bowel motions (stools) and makes them softer and easier to pass (like a natural lubricant).

Taking fibre without drinking sufficient fluid (e.g. water, tea, herbal tea etc.) will result in the stool setting hard. So, unless we are careful to balance fibre and fluid intake, having more fibre can actually make IBS worse. We don't need to drink huge amounts of water, just enough to pass pale yellow urine a sufficient number of times a day (5 times is a sensible target). By the way, drinking large amounts of fluid by itself, without fibre, does very little for constipation - just makes us pee more!

20.3.5 How might fibre be important in Bloating and IBS
Eating the amount of fibre that your tummy is 'happy' with is one of the aims of self-managing IBS gut symptoms:

• Too much fibre = loose / frequent stools, tummy pain, excess gas, bloating

• Enough fibre = soft, firm stools, 'normal' amount of gas (we all pass some gas!)

• Too little fibre (and fluid) = hard / pellet stools, tummy pain, straining

For many people, eating the 'right' amount of fibre is the key to resolving their gut symptoms. The 'right' amount for one person may be different than the 'right' amount for another.

A fibre-modified diet needs to be followed for a period of time to find out what the right amount of fibre might be. Following a diet that modifies the amount of fibre eaten can bring results within 2-4 few weeks. It is important not to judge things too soon and give up before the diet has had enough time to work as well as it potentially can, particularly if constipation is our issue.

Once symptoms have improved, it is then just a matter of managing them by continuing to eat the right amount of fibre and generally eating sensibly i.e. eating what agrees with your tummy.

20.4 Proteins
Proteins are used to make muscle and the enzymes needed for the thousands of different processes in the body. Protein is also the material used for holding everything together in the body e.g. skin, ligaments.

Protein doesn't usually cause an 'intolerance' problem in people (but it can do in some cases). Foods rich in protein include meat, fish, eggs, beans, lentils, peas, nuts. Dairy foods, such as milk, yoghurt and cheese are also a good source of protein.

Things are slightly complicated though by the fact that many foods contain a combination of 'building blocks'. Foods such as lentils are rich in fibre and this can cause tummy symptoms (e.g. bloating, diarrhoea, excess gas). Also, the fat around meat (e.g. fatty pork) can upset the tummy, giving rise to pain or discomfort. Also, . Protein and creatine supplements, however, can cause gut issues with Bloating and IBS.

So, Protein is generally okay for IBS, it is other components in food (i.e. carbohydrates, fibre and fats) that usually cause the problems

20.5 Why certain Foods cause Bloating and IBS
The key word is fermentation as this process of digestion is a major cause of tummy symptoms.

Fermentation is the process by which normal bacteria breakdown food components e.g. fibre, fructans, galactans, polyols. What our normal bacteria do in the colon is not too dissimilar to the fermentation process by bacteria in a compost heap.

Fermentation in the colon is a very good thing – products formed by bacteria during the process help to keep us healthy (in particular, small amounts of Fatty Acids help nourish the cells lining the lower bowel). But, you can have too much of a good thing!

In some people, fermentation can contribute to excessive wind, bloating, tummy discomfort and loose (and / or frequent) stools. It's not all about looser bowels by the way; the gasses that are given off, in particular methane, may also contribute to constipation. A number of different food components can be fermented by bacteria.

But, fermentation is not the cause of all gut symptoms. Not getting enough fibre and fluid (hydration), eating too much fat and other food components can cause symptoms e.g. hard stools, tummy pain, loose / frequent stools.

20.5.1 Fermentable carbohydrates
Gut fermentation is the process whereby gas and other things are produced as food is being digested (broken-down into smaller parts) by bacteria. It is similar to what happens when beer is being brewed.

There are several different food components that are fermented by bacteria in the gut. One of the by-products of fermentation is gas, which can cause tummy pain (by stretching the gut), bloating and excess 'wind'. Another by-product is fatty acids that can act like a laxative.

20.5.2 Lactose: This is the sugar naturally present in milk and milk products (whether cow, goat, sheep or human milk). As babies, all of us have an enzyme tool (called lactase) on the lining cells of our small bowel which breaks up the lactose chain of molecules, so that it can be absorbed. The lactase enzyme works as 'scissors, cutting up the lactose into smaller pieces that can be transported or handled by the cells lining the gut.

As we grow into adulthood, our ability to make lactase can become less, particularly if we are of Chinese or Japanese heritage. Not making enough lactase makes lactose indigestible. This means that it cannot be absorbed in the small intestine, so it ends up in the colon where bacteria ferment it.

During a bad episode of food poisoning, gut cells that make lactase can be 'stripped' away and then only partially re-grow, which will compromise a person's tolerance to milk and milk products - sometimes this change can be permanent.

20.5.3 Fructose: Sometimes referred to as 'fruit' sugar - fructose is actually one of several different types of sugar in fruit. Very importantly, fructose may also be present as a calorific sweetener in a range of foods and drinks.

The process that helps us to absorb fructose in the small intestine is complex and gets easily overwhelmed, which results in fructose not getting absorbed. So, consuming too much fructose in one go can result in a lot of this sugar ending up in the colon, where it is fermented.

For a fructose molecule to get absorbed it needs a "buddy" to help it along, the buddy is another sugar (glucose): one fructose molecule hooks-up with one glucose molecule and gets 'escorted' by the glucose through the gut wall. Foods which naturally contain slightly more glucose than fructose don't cause problems. But, if a whole bus-load of fructose and glucose molecules arrive at the same time, the gut gets overwhelmed and can't cope, which can trigger gut symptoms.

Foods that contain large amounts of fructose, regardless of the presence of glucose molecules, can cause problems - the fructose can't be absorbed and so it ends up being fermented in the colon. This is not a problem for many, but for some of us, fermentation of fructose can cause excess 'wind', bloating, tummy pain and loose / frequent stools.

One key "hidden" ingredient to look out for as a possible cause of bowel symptoms such as gas or diarrhoea is High Fructose Corn Syrup (HFCS) which is increasingly found in soft-drinks, breakfast cereals and other foods.

20.5.4 Fructans: These are related to fructose and actually are a string of pure fructose molecules strung together in a chain like a string of beads. We can't break up the links in these chains (i.e. digest them), which means that we can't absorb them, so fructans end up in the colon, where they get fermented.

Foods that are high in fructans include artichokes, asparagus, leeks, garlic, onions and wheat - wheat also contains gluten. This last point is interesting as it may be that going gluten-free might help many people because they're avoiding the fructans and actually have nothing to do with the gluten itself!

20.5.5 Galactans: These are galactose (another type of sugar) molecules linked together in a chain like a string of beads (much like fructans). We can't digest the galactan chains and so they also end up in the colon, where they are fermented.

Galactans are found in pulses e.g. baked beans, kidney beans, chickpeas.

20.5.6 Sugar alcohols: We cannot digest or absorb these food components, so they too end up in the colon, where they are fermented. Sugar alcohols include sorbitol, mannitol and xylitol and are naturally present in some fruits and vegetables. Importantly, they are also used as low-calorie sweeteners in a range of foods, drinks and confectionery such as sugar-free gum and snack-bars. They are very definitely something that you need to look out for if diarrhoea, bloating or gas are the problem.

20.5.7 Other sugars: Some foods have a non-absorbable sugar called inulin or FOS (fructo-oligosaccharide) added. These can cause problems for the same reason as outlined above.

20.6 Other dietary causes of symptoms in Bloating and IBS
Earlier in this chapter we talked about how Fibre and Fats can cause symptoms, but a number of other things in the diet can cause gut trouble. Sometimes the trigger is dose-dependent, which means that a small amount is tolerated but a larger amount triggers problems.

Caffeine, alcohol, fizzy drinks, sugar-free chewing gum can be troublesome to the gut - the Starter diet gut-friendly eating habits and better food choices encourages restriction of such foods.