What is irritable bowel syndrome (IBS)?

What is irritable bowel syndrome (IBS)?

IBS is a condition that affects the digestive system. Although anyone can develop it, the condition is more likely to affect young people and women. Furthermore, severity varies. As a result, some people suffer from minor symptoms, while others suffer from symptoms that play havoc with daily life.

Unfortunately, 7-21% of people suffer from IBS. Furthermore, women are twice as likely to have this condition compared to men.(1)

Usually people with IBS have typical bowel movements some days and abnormal ones on others. Moreover, the 3 types of IBS depend on the abnormal bowel movements experienced:

• IBS with constipation (IBS-C). Hard stools more than 25% of the time and loose stools less than 25% of the time.
• IBS with diarrhoea (IBS-D). Hard stools less than 25% of the time and loose stools more than 25% of the time
• IBS with mixed bowel habits (IBS-M). Hard stools more than 25% of the time and loose stools more than 25% of the time

Fortunately, IBS doesn’t damage your digestive tract or raise your risk for colon cancer, however it is a chronic condition that requires long term management.(2)

What causes irritable bowel syndrome (IBS)?

Scientists don’t know the definitive cause, however they think a combination of factors can lead to IBS:

Dysmotility: Irregularity with how gastrointestinal (GI) muscles contract and transport food through the GI tract. The walls of the intestines are lined with layers of muscle that contract as they move food through your digestive tract. Strong long lasting contractions can cause bloating, diarrhoea and gas. Meanwhile, weak contractions can slow food passage and lead to constipation

Brain-gut dysfunction: As a functional GI disorder, IBS is caused by disruptions in the way your brain and gut interact with one another. These problems cause your digestive tract to be very sensitive. Moreover they change how your bowel muscles contract. Poorly coordinated signals between the brain and the intestines can cause the body to overcompensate to changes that normally occur in the digestive process, resulting in pain, diarrhoea or constipation.

Visceral hypersensitivity: When the abdomen stretches, extra-sensitive nerves located in the digestive system may cause you to experience a significant amount of discomfort.(3)

You may also be at higher risk of developing IBS if you have:

• Family history of IBS
• Stress or anxiety
• Food intolerance
• History of abuse
• Severe digestive tract infection

What are the symptoms of irritable bowel syndrome (IBS)?

Symptoms of IBS aren’t necessarily persistent. They can resolve, only to come back. However, some people report having continuous symptoms.

In general, the colon muscle contracts more than in people without the condition. As a result, these contractions cause pain. Occasionally pain associated with IBS can feel like cramping. In general, this cramping causes the following symptoms:

• Pain relief post bowel movement
• Inconsistent frequency of bowel movements
• Varying stool consistency (e.g. diarrhoea and constipation)
• Abdominal cramps
• Bloating
• Excess gas
• Mucus in the stool (4)

In people with IBS, it’s not uncommon to have episodes of both constipation and diarrhoea. Fortunately, symptoms such as bloating and gas typically go away after a bowel movement.

Women's symptoms often flare up during their periods. Unfortunately, these symptoms commonly happen repeatedly, which can cause high levels of stress. However, learning management techniques helps to gain control over flare-ups, leading to improved physical and mental health.

If you suffer from GI discomfort, have a persistent change in bowel habits, or show other signs/symptoms of IBS, please see your doctor. The first step of diagnosis is a medical history and a physical exam. Additionally, it’s important to pay close attention to your symptoms as your doctor will ask about them.

Treatment of irritable bowel syndrome (IBS)

There is no ‘one size fits all’ treatment for IBS, however most people can find a treatment that works for them. Moreover, doctors personalise treatment plans based on individual needs.

A few people with IBS suffer from significant symptoms. As a result, some people can manage them by using typical treatment options such as dietary and lifestyle changes. However, people who suffer from more significant symptoms may require counselling and medication.

Low FODMAP diet

The role of food allergies and intolerances in IBS isn't fully understood. Moreover, food allergies rarely cause IBS, however many people have worse symptoms when they eat or drink certain foods or beverages. This includes wheat, dairy, citrus, legumes and carbonated drinks.

The low FODMAP diet is part of the therapy used for those with IBS. In addition, research has found that it reduces symptoms in up to 86% of people.(5)

This therapy proposes single food avoidance and exclusion diets e.g. low fermentable oligo-saccharides, di- saccharides, monosaccharides and polyols. These are non-digestible small carbohydrates that force water into your digestive tract. Furthermore, because they’re non-digestible, gut bacteria ferment them, increasing gas and short-chain fatty acid production.(6)

FODMAPs are found in a wide range of foods. Some foods contain just one type, while others contain several. Examples of foods that fall into the four groups of FODMAPs are:

• Oligo-saccharides: wheat, nuts, legumes, garlic, onion
• Di-saccharides: milk, yogurt, soft cheese, cream (foods containing lactose)
• Monosaccharides: apples, pears, watermelon, mango, honey, agave (foods containing fructose)
• Polyols: cauliflower, stone fruits, mushrooms, peas (foods containing mannitol and sorbitol) (7)

The total daily intake of FODMAPs in an average diet ranges from 15-30g per day. All FODMAPs are potential triggers. Fortunately, not all FODMAPs aggravate abdominal symptoms in a person with IBS.

To summarise, the low-FODMAP approach is not simply an exclusion diet. It is also a tool used to diagnose a person's tolerance to certain foods. Therefore, this allows the individual to eliminate these foods from their diet and to make positive changes towards their lifestyle.

Related readings

• 11 delicious low FODMAP vegan recipes
• How to test for gluten intolerance