A complete guide to IBS

A complete guide to IBS

 What is IBS? 

Irritable Bowel Syndrome (IBS) is a gastrointestinal disorder that causes several symptoms such as abdominal pain, bloating, and changes in bowel habits (diarrhoea, constipation, or both) that can have a significant impact on your life if not treated or managed correctly. 

IBS is typically a lifelong condition which there is currently no cure for; however, dietary modifications, lifestyle changes and medicines can help to ease the symptoms and manage the condition. 

Did you know: Affecting 10-15% of the global population, IBS can significantly impact your quality of life. The exact cause of IBS is not known, most research suggests it is the result of disturbances within the gut-brain axis and other psychological, environmental, and lifestyle factors. 

Symptoms of IBS 

The symptoms of IBS can appear to be quite intermittent and can come and go over time. Typically, symptoms can last anywhere from a few hours to days, weeks and even months. 

Common Symptoms:  

These include abdominal pain, bloating, gas, diarrhoea, and constipation. Symptoms can range from mild to severe and can be heightened by stress or food intake. Symptoms will differ from person to person; some individuals may only experience one symptom, whilst others may experience several at the same time. 

Severe Symptoms:

While not life-threatening, severe IBS can significantly impair the quality of life, causing pain, uncontrollable bowel movements, and severe fatigue. 

How IBS Symptoms Differ from Other Digestive Disorders

Unlike inflammatory bowel diseases like Crohn’s or ulcerative colitis, IBS does not cause inflammation, ulcers, or other damage to the bowel. Its symptoms are less severe but more chronic. 

Causes of IBS 

Whilst the cause of IBS is not completely understood, research suggests it's a combination of factors: 

  • Gut-Brain Axis Disruption: Altered communication between the brain and the digestive system can cause IBS symptoms. The gut-brain axis is a bi-directional communication pathway, meaning that the brain passes messages to the gut, and the gut passes messages to the brain. In people with IBS, disturbances and disorganisation of the messages sent via the gut-brain axis are believed to be a contributing cause of IBS. 
  • Abnormal contractions within the intestine: The walls of the intestine are lined with muscles, when we eat food, those muscles contract to move food along our digestive tract. Contractions that are stronger, weaker, or longer than usual can cause symptoms such as bloating, diarrhoea and constipation. 
  • Visceral Hypersensitivity: Increased sensitivity to pain in the gut, meaning that the normal functioning of your digestive organs may cause pain and discomfort. 
  • Infections: IBS can develop from an infection from a virus or bacteria which causes a severe bout of diarrhoea, also called gastroenteritis. 


Dietary Triggers: 

  • FODMAPs: Short-chain carbohydrates (sugars) that are poorly absorbed by the small intestine and can ferment, causing gas and bloating. These carbohydrates also draw water towards them, and so can lead to diarrhoea. Examples of foods which are high in FODMAPs include lactose-containing dairy, gluten-containing cereals, onions, garlic, and various other fruits and vegetables. 
  • Gas-producing foods: Brassica vegetables, as well as beans, lentils and pulses, can cause an overproduction of gas in the large intestine, leading to gas and bloating.  
  • Inadequate or sub-optimal fibre intake. Fibre can help to not only soften a hard stool (or thicken up a loose one), but can also encourage your intestine to push food along more effectively, significantly reducing constipation. Different fibres can also have varying degrees of fermentability, meaning manipulating your fibre consumption can reduce gas and bloating too.  
  • Stress and Anxiety: Psychological stress can heighten IBS and other gastrointestinal symptoms by affecting gut motility and sensitivity. 
  • Hormonal Changes: Fluctuations during menstrual cycles can impact bowel function, one of the main factors in why IBS is more prevalent in women. 

Who is most at risk? 

  • Young Age: IBS commonly develops in late adolescence or early adulthood, typically before the age of 50. 
  • Female Gender: Women are more than twice as likely to be diagnosed with IBS than men. Factors such as hormone fluctuations and menopause are contributing factors. Our medical guide, Understanding IBS in Women details the symptoms, challenges and management techniques for women suffering from IBS.
  • Family: Whilst there is currently no research to suggest IBS is based on genetics, for families with a history of IBS, it is more likely that a shared lifestyle is a contributing factor to developing IBS. 
  • Psychological Factors: A history of anxiety, abuse, depression, or other psychiatric disorders is commonly linked with IBS. 

How is IBS diagnosed? 

Diagnostic Criteria: Diagnosis is typically made based on symptoms and ruling out several closely related conditions. The Rome IV criteria are used in clinical practice, which requires recurrent abdominal pain, on average, at least one day per week in the last three months, associated with two or more of the following for a diagnosis to be made: a change in frequency of stool, or a change in form (appearance) of stool. 

Tests and Procedures: These may include blood tests, stool tests, colonoscopy, and lactose intolerance tests, to rule out other conditions like celiac disease or inflammatory bowel disease. IBS in and of itself cannot be officially diagnosed with a laboratory test; instead, the Rome IV criteria, along with ruling out other causes, allows diagnosis. 

Gut microbiome test: Whilst a gut microbiome test will not diagnose you with IBS, it can tell you if you are at risk of developing IBS by measuring the bacteria present within your microbiome. There is evidence to suggest that gut dysbiosis (an imbalance of bacteria within the gut) plays a role in the development of IBS, by testing your microbiome, we can compare your microbiome profile against individuals who suffer from IBS and assess your risk of developing the condition. 

Identifying IBS from other digestive disorders 

Irritable Bowel Syndrome (IBS) is identified from other digestive disorders by its unique symptoms and patterns. IBS typically presents cramp-like abdominal pain that is often relieved by bowel movements and is closely linked to changes in bowel habits, such as alternating patterns of constipation and diarrhoea.  

Treatment and management 

Dietary Management of IBS 

Foods to Avoid: This is highly individualised and should be discussed with a dietitian to allow you to identify the foods you should specifically avoid. Examples of potential triggers include gas-producing foods, FODMAP and different types of fibres in varying quantities. Understanding what triggers your IBS is essential for managing the condition long term as there is currently no cure for it. 

Beneficial Foods for IBS: Foods high in soluble fibre, low-FODMAP fruits and vegetables, lean proteins, and probiotics can be beneficial. 

The Role of Fiber:

A high-fibre diet can help to manage the symptoms of IBS, however, you must be consuming the correct type of fibre based on the symptoms your IBS is causing.

Soluble fibre can help with IBS symptoms in several ways as it can not only soften your stools and make them easier to pass but can also thicken a loose stool. 

A sudden increase in soluble fibre can cause your IBS symptoms to worsen, and therefore it is important to ease yourself into an increased daily intake of soluble fibre. 

Insoluble fibre can also help with IBS symptoms; in particular, constipation-predominant IBS. It does this by bulking up your stool, allowing it to push against the sides of your bowel and therefore triggering the bowel to constrict, pushing the stool along the bowel faster.  

Equally, the fermentability of the fibre you are consuming will have a direct impact on whether it is beneficial for your IBS symptoms or not. Many fibres are considered moderate-highly fermentable, and overconsumption of these can lead to increased gas, bloating and pain. 

Read our complete guide on effectively managing IBS through diet.

Lifestyle and Home Remedies 

Stress Management: Relaxation exercises, meditation, yoga, and cognitive behavioural therapy can help manage stress-related triggers. 

Exercise and IBS: Regular exercise can improve bowel function and reduce stress. 

Importance of Sleep and Routine: Adequate sleep and a routine can help regulate bowel function. 

Medical Treatments for IBS 

Medications: These include fibre supplements, laxatives, anti-diarrhoeal medications, antispasmodic agents, and certain antidepressants for pain and depression. 

Therapies and Alternative Treatments: Probiotics, psychological therapies, acupuncture, and peppermint oil are effective for some people.

Medicine is not the first line treatment option for IBS, typically; your GP will advise dietary and lifestyle changes to help reduce your symptoms before prescribing/recommending medicine.

Living with IBS and outlook 

Whilst IBS does not reduce life expectancy it can have an impact on your quality of life. There is currently no cure for IBS, the condition requires a multifaceted approach to manage the condition and reduce the severity of symptoms. 

Anyone engaged in the long-term management of IBS can also benefit from the below: 

  • Education and Awareness: Understanding the nature of IBS and recognising personal triggers can help you manage the severity of the condition. 
  • Regular Medical Follow-Up: Ongoing communication with healthcare providers is crucial for effective management. 
  • Support Systems: Joining IBS support groups or seeking psychological counselling can help you discover and share coping strategies. 

Effective management of IBS requires patience and persistence, as different strategies work for different individuals. It may take time for you to find what works for you, however; with the right approach, many people with IBS find significant relief and lead fulfilling and normal lives. 

When to See a Doctor 

  • Persistent Symptoms: If symptoms are continuous and affect quality of life. 
  • Red Flags: Unexplained Weight loss blood in your stool, awakening at night to open your bowels or a family history of gastrointestinal diseases warrant immediate medical attention. 

Can You Suddenly Develop IBS? 

Yes, it is possible to develop Irritable Bowel Syndrome suddenly. The onset of IBS can be abrupt, often triggered by factors like a severe bout of gastroenteritis (often referred to as post-infectious IBS), significant stress, or changes in diet. However, in some individuals, the onset can be more gradual. 

Can You Prevent IBS? 

While there is no guaranteed way to prevent IBS, it is possible to reduce the risk of developing the condition or lessen the severity of symptoms: 

  • Diet: Avoiding trigger foods, such as high-gas foods, gluten, or lactose, if sensitive. Understanding your trigger foods can significantly reduce your symptoms. 
  • Stress Management: Engaging in regular exercise, mindfulness practices, or counselling. 
  • Gut Health Maintenance: Regular testing and maintenance of your gut microbiome to ensure there is no presence of gut dysbiosis can significantly reduce your risk of developing IBS. 

Can IBS be Cured? 

Currently, there is no cure for IBS. However, many people can effectively manage symptoms through lifestyle modifications, dietary changes, and, in some cases, medication. The treatment is individualised and often requires a tailored approach, including dietary adjustments, stress management, and sometimes psychological therapy. 

Can IBS Go Away on Its Own? 

IBS is a chronic condition, but its symptoms can fluctuate over time. Some individuals may experience periods of remission, where symptoms are minimal or absent. These periods can occur spontaneously or because of lifestyle changes. However, IBS symptoms can also return or worsen, often triggered by stress or dietary factors. Those with IBS need to develop a long-term management plan with their healthcare provider. 


IBS is a chronic but manageable condition. Understanding its nature, identifying personal triggers, and adopting a multifaceted treatment approach is key to living well with IBS. 

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IBS and Diet Management
Understanding IBS in Women