Ben Squires


The low carb diet for irritable bowel

The low carb diet for irritable bowel

The "Low-FODMAPs" diet is a confusing but scientifically proven to help with irritable bowel problems.

Low-FODMAPs is perplexing because it requires you to avoid a long list of fermentable carbohydrates that are high in oligosaccharides (e.g. simple sugars), disaccharides (e.g. lactose), monosaccharides (e.g. high-fructose fruit and vegetables), and polyols (e.g. artificial sweeteners). 

Proven to be very useful in managing irritable bowel syndrome, if you want to try this diet, it is best done in consultation with their doctor or nutritionist.

However, there's a need to differentiate between irritable/intolerant bowels and bowel inflammation diseases.

Indeed, Low-FODMAPs isn't a cure-all. The science behind it is specific to hypersensitivity and intolerance, which results in Irritable Bowel Syndrome (IBS), rather than Inflammatory Bowel Diseases such as Crohn's disease and ulcerative colitis (to which Low-FODMAPs has not been proven advantageous). 

When you have an intolerant bowel, your system is not inflamed but hypersensitive to some of those fermentable carbohydrates. Low-FODMAPs works by cutting all of the most likely culprits out of your diet completely, and then slowly adding them back in (after about six weeks on the diet) to see how your bowels react to individual foods. 

This is what we call an "elimination diet"; you're trying to eliminate what doesn't upset your bowels so you can find out exactly where your problem(s) lie.

In recent years, the trends of gluten-, dairy-, and now sugar-free diets have surged in popularity. Those who are hypersensitive to any of these likely have a "carbohydrate intolerance". 

No, this isn't just another fad that gives you an excuse to say no to bread: It's a scientific term that means you're unable to digest certain carbs because you lack the appropriate intestinal enzymes to do so. 

If you're one of these people, the result of eating carbohydrates your body doesn't like often leads to IBS. This means you need to do "number twos" more than three times per day, or you get regularly constipated and can't go at all. 

Your stool quality may also be abnormal (it may be watery like diarrhoea). IBS affects the microflora in your stomach – you may have heard the term "leaky gut" online or in health magazines – which means the control that lines the small intestines "leaks" and doesn't work properly. 

The good news is, IBS is manageable. The Low-FODMAPs diet, although proven effective in three out of four people who try it (as reported in Gastroenterology journal), is not a palatable for everyone. Many will find it easier to eliminate one type of irritable carb at a time.  

This is the reason the gluten-free industry has become so popular: While only about 1 per cent of people have celiac disease, surveys have reported around 30 per cent of people get upset stomach/bowels after eating gluten. Reducing or cutting it out allows many people to control their IBS symptoms. 

If gluten doesn't seem to be your greatest evil, do try omitting all dairy – e.g. milk, cheese, ice cream, yoghurt – from your diet for several weeks or a few months. If it has little-to-no effect (or you'd prefer to try it the other way around), omit all sugars that are processed, and those that naturally occur in high volumes, i.e. more than five grams of sugar per 100g. 

Carbohydrate intolerances are not the sole cause of IBS, though. Sufferers are also likely hypersensitive to caffeine because of its diuretic effect, and sometimes alcohol, smoking, high amounts of fat (like in fried foods). You should play the same elimination game with these to gauge your body's reactions. 

Foods that shouldn't upset the bowels, on the contrary, include all meat, low-fructose vegetables like leafy greens, capsicum, and tomatoes, potatoes and kumara, rice and quinoa, and dairy if it hasn't proved problematic in the past. 

Importantly, one of the major factors in upset bowels is stress. Medical journals such as Gut have been publishing studies finding very strong correlations between it and IBS.

Alongside your diet, it is advisable to address your mental health, too, in any quests to manage upset bowels.   

If your bowel health is compromised beyond the realm of IBS and you've been diagnosed with an Inflammatory Bowel Disease like Crohn's or ulcerative colitis, you will need medication and possibly surgery.

Any diet changes should be discussed with your doctor, not addressed on your own.

Written by Lee Suckling, who has a master's degree specialising in personal-health reporting.

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