Irritable Bowel Syndrome (IBS): Causes, Symptoms, Treatment, and Low FODMAP

Updated: Nov 7, 2020


Irritable bowel syndrome, or IBS, is a functional disorder effecting the gut and may be more common than you think, being around 11% of the adult population - So you are not alone! IBS can significantly affect a person’s quality of life AND comparable to other chronic diseases, that cause distress and anxiety on a daily basis, often creating barriers that prevent a person engaging in a fulfilling career and disruptions to family life.

Unfortunately, there is no absolute cure for IBS - BUT there are various treatments and diet therapy that can help manage your symptoms, with great success!

IBS is now so widespread, with the number of patients being diagnosed with this syndrome increasing yearly, AND why we need robust research and effective treatments to try and give sufferers real, longterm relief.

In this post, we will cover the causes, symptoms, and a selection of treatment options shown to improve IBS effects, including the increasingly popular therapy called the

Low FODMAP diet.

Causes irritable bowel syndrome

The exact causes that trigger IBS are still not clearly understood, with suggestions towards a genetic, stress, hormone imbalance or an immune disorder. A disturbance between the brain-gut axis seeming to be a common contributing factor that predisposes an individual to IBS.

Common Risk Factors

  • Smoking

  • Alcohol consumption

  • Psychological and physical stress

  • Imbalanced diet

  • Hormonal imbalance


The symptoms of IBS effect people in many different ways and a person can go through periods of flareups and remissions that another may not experience. Symptoms can be debilitating in many individuals, but may be mild or moderate in others. In addition, IBS is often associated with other comorbidities such as pain syndromes, overactive bladder and migraine headache, or psychiatric conditions including depression, anxiety and stress often triggered by a significant life-changing event.

Red Flag Symptoms

You should seek professional, medical advice if you experience one or more of the following symptoms presented with IBS:

· Changes in bowel habits

· Passing blood from back passage

· Unintentional weight loss

· Family history of bowel or ovarian cancer

Clinical Presentation

IBS is commonly present with one or more of the following:

· Abdominal pain

· Cramping

· Sensation of bloating – usually disappears after passing a bowel movement

· Constipation

· Diarrhoea

· Gas

Subtypes of IBS

IBS is diagnosed based on symptoms, and a distinction is made between the following:

· IBS with pain or discomfort and constipation (IBS-C)

· IBS with diarrhoea (IBS-D)

· Mixed IBS being a combination of all symptoms (IBS-M)

· Unsubtyped IBS (IBS-U)

Treatment options for IBS


Daily consumption of probiotics help increase the availability of healthy bacteria in the gut that may lead to the following benefits:

  • Improved bowel movement

  • Improved digestion

  • More efficient removal of chemicals and toxins from the intestinal tract

  • Reduced risk of infections such as E.coli, Salmonella, Shigella and Campylobacter

  • Improved symptom relief of IBS


Fibre is known to have many positive effects, especially along the digestive tract. Fibre is complex carbohydrates that cannot be absorbed along the gut, meaning it is later disposed of as waste products. This may not seem very significant however, it has many benefits on the body, including the control of IBS symptoms, the cholesterol lowering effect and it feeds your resident gut bacteria, making it stronger and more effective. In fact, some studies have even shown that a fibre-rich diet may reduce the risk of colon cancer.

The amount of fibre depends on each individual and most of us don't eat nearly as much as we should being approximately 18g a day, a good rule of thumb is around 30g. A great source is green leafy vegetables and some grains that contain both types of fibre (soluble and insoluble).

If you think you are not getting enough fibre in your diet it might be a good idea to speak to a dietitian HERE


Regular exercise has been shown to decrease the frequency and activity of IBS as it improves hormonal regulation, bowel movements, and gastric emptying. The type of exercise you perform is not as important as consistency, so in that case you should opt for sports or workout routines that you really enjoy, so you can keep doing it for a long time.


Hatha yoga, meditation and pilates are often associated to improved digestion including reducing stress as well as toning the body and resting the mind.

A personal trainer can help design a workout best suited to your abilities and improve mental health by increasing the release of endorphins, helping you feel great about yourself.

First line dietary restrictions for IBS

Some people may experience symptom relief after changing diet and lifestyle habits including restricting specific food and drink for a period of time before reintroduction. Below is an example of some 1stline restrictions:

· Smoking

· Alcohol

· caffiene

· Spicy food

· Rich or Fatty food

Low FODMAP diet - When 1st line options don’t quite cut it.

The low FODMAP plan focuses on excluding many foods from a persons daily intake to settle the gut and avoid IBS flareups during the elimination phase. The reintroduction phase is a carefully managed program to help identify accurate food triggers to avoid, and optimise the diet to prevent nutritional deficiencies.

The acronym ‘FODMAP’ describes a wide range of foods that are shown to cause bloating, gas, and abdominal cramping, which is especially unwanted for patients with IBS and meaning of FODMAP stands for:

  • Fermentable

  • Oligosaccharides

  • Disaccharides

  • Monosaccharides

  • AND

  • Polyols

The list is extensive but here are a few examples of these foods:

  • Fermentable

  • Oligosaccharides: wheat, legumes, fruits, and vegetables

  • Disaccharides: some dairy and all lactose-rich products.

  • Monosaccharides: figs, mangoes, honey, and agave nectar.

  • Polyols: blackberries, lychee, and low-calorie sweeteners.

The low FODMAP diet has shown to be effective and offers significant benefits to IBS patients strong evidence to support the efficacy of a low FODMAP diet. However, the symptom with the least improvement was constipation. Constipation has long been associated with a low fibre intake, and a typical low FODMAP diet can often be lacking in fibre content.”

Due to the complexity of this diet, the plan diet should be managed by a dietitan that has been fully trained and qualified to deliver the Low FODMAP diet.

If you need guidance to help you manage your IBS or would like to commence on the Low FODMAP diet, do not hesitate to contact us HERE

For any questions about IBS or low FODMAP, feel free to ask us in the comment section at Core Nutrition Specialists

16 views0 comments

Recent Posts

See All