Irritable bowel syndrome (IBS) is a common digestive condition that affects how the gut works, causing symptoms such as abdominal pain, bloating and changes in bowel habits.

Unlike conditions that cause visible damage to the digestive tract, IBS is classified as a disorder of gut-brain interaction (DGBI). This means symptoms are linked to changes in communication between the brain and the digestive system, rather than a structural problem that would typically appear on scans or during a colonoscopy.

'IBS is a disorder associated with an imbalance in the relationship between the central nervous system and the enteric nervous system,' explained Dr Edmundo Rodriguez-Frias, a double-board-certified gastroenterologist and medical contributor at Full of Life.

'People who have IBS may find their bowels to be hypersensitive and therefore experience irregularities in bowel movements and feelings of discomfort.'

IBS is thought to affect around 5–10% of people worldwide, although many cases may go undiagnosed because symptoms vary significantly between individuals.

Importantly, IBS symptoms are real. Despite outdated misconceptions that the condition is 'all in your head', experts now understand that IBS involves complex biological processes affecting digestion, pain sensitivity and bowel function.

Common IBS Symptoms to Look Out For

IBS symptoms can differ from person to person and may come and go over time. Some people experience mainly constipation, while others have frequent diarrhoea or a combination of both.

Common symptoms include:

  • Abdominal pain or cramping
  • Bloating and abdominal swelling
  • Excessive gas
  • Constipation
  • Diarrhoea
  • Changes between constipation and diarrhoea
  • A feeling of incomplete bowel emptying
  • Urgency to use the toilet

Dr Rodriguez-Frias said many people notice their symptoms fluctuate depending on factors such as food intake, stress, infections, hormonal changes and disrupted sleep.

For some, symptoms may be mild and occasional. For others, IBS can significantly affect work, relationships, social activities and emotional wellbeing.

'Symptoms experienced by those afflicted with IBS are genuine and can significantly impair one's overall quality of life, including professional productivity, social functioning and emotional stability,' he said.

Why Does IBS Happen?

Menstrual Cramps / Endometriosis
IBS has no single cause. Experts say changes in gut sensitivity, microbiome, digestion and the brain-gut connection may all contribute to symptoms. Katemangostar via Magnific

There is no single cause of IBS. Researchers believe several factors may contribute, including changes in gut sensitivity, intestinal movement, inflammation, gut bacteria and communication between the gut and brain.

Dr Savita Srivastava, a Yale-trained gastroenterologist and microbiome specialist, said IBS is now understood as a condition with multiple possible biological drivers.

'We now understand that IBS has many root causes that may originate along the brain-gut axis,' she said.

These may include:

  • Miscommunication between the brain and gut
  • Visceral hypersensitivity, where the gut becomes overly sensitive
  • Changes in intestinal movement
  • Micro-inflammation
  • Alterations in the gut microbiome
  • Small intestinal bacterial overgrowth (SIBO)

Stress is often linked with IBS flare-ups, but it does not directly cause the condition.

Instead, stress can influence how the brain communicates with the gut, potentially worsening symptoms in people who already have IBS.

Symptoms in Women: Hormones May Play a Role

Hormonal changes can influence digestive symptoms, and some women notice IBS symptoms becoming more noticeable during certain stages of life.

According to Dr Srivastava, perimenopause can be an overlooked period when digestive changes appear.

'Many women who never had digestive issues in their 20s or 30s suddenly develop intense bloating, constipation, altered bowel habits and food intolerances in their late 40s,' she said.

During perimenopause, fluctuations in oestrogen levels may affect bowel movement speed and changes in the gut microbiome, potentially contributing to new or worsening symptoms.

However, new digestive symptoms during midlife should not automatically be attributed to hormonal changes. It is important to rule out other conditions, particularly if warning signs are present.

When Should You See a GP About IBS Symptoms?

Because IBS symptoms can overlap with other digestive conditions, doctors stress the importance of proper assessment before assuming IBS is the cause.

Dr Srivastava said her role as a gastroenterologist is not simply to label symptoms as IBS but to identify conditions that may look similar.

'IBS shares an overlapping symptom profile with several serious organic conditions that require a completely different treatment approach,' she explained.

You should speak with your GP if you experience:

  • Unexplained weight loss
  • Blood in your stool
  • Persistent vomiting
  • Fever
  • Anaemia or iron deficiency
  • Symptoms that wake you from sleep
  • A family history of bowel cancer, inflammatory bowel disease or coeliac disease
  • New IBS-like symptoms developing later in life

These symptoms may require further investigation to rule out conditions such as inflammatory bowel disease, coeliac disease, microscopic colitis or other digestive disorders.

How Is IBS Diagnosed?

There is no single test that confirms IBS. Instead, doctors usually make a diagnosis based on symptoms, medical history and whether a person meets recognised diagnostic criteria, such as the Rome IV criteria.

Depending on symptoms, a GP may recommend blood tests, stool tests or other investigations to exclude conditions that mimic IBS.

Dr Rodriguez-Frias explained that IBS should not simply be diagnosed because no other cause has been found.

'IBS is not considered a primary diagnosis when "nothing" else has been determined,' he said.

A careful evaluation helps ensure patients receive the right support while avoiding unnecessary procedures.

How Can IBS Symptoms Be Managed?

There is currently no single cure for IBS, but many people can significantly improve symptoms through personalised treatment.

Management options may include:

Dietary changes

Some people benefit from identifying individual food triggers. A supervised low-FODMAP diet, which reduces certain fermentable carbohydrates, may help some patients manage bloating and discomfort.

However, experts recommend working with a healthcare professional, as overly restrictive diets can create nutritional problems.

Lifestyle changes

Regular physical activity, improved sleep and stress management may help regulate gut function and reduce flare-ups.

Medication

Depending on symptoms, doctors may recommend medication to manage constipation, diarrhoea, abdominal pain or bloating.

Gut-brain therapies

Because IBS involves communication between the brain and gut, psychological approaches such as cognitive behavioural therapy, mindfulness and gut-directed hypnotherapy may help some people.

Dr Srivastava said effective IBS treatment often requires a team-based approach involving gastroenterologists, dietitians and GI psychologists.

Key Takeaways

IBS is a common but complex digestive condition that can have a significant impact on daily life. Symptoms such as bloating, abdominal pain and bowel changes should not be dismissed as simply having a 'sensitive stomach'.

While IBS is not linked to structural damage in the gut, the symptoms are genuine and often require personalised management.

If symptoms persist, worsen or occur alongside warning signs such as unexplained weight loss, bleeding or fever, speaking with a GP is essential.

With the right diagnosis, lifestyle adjustments and treatment plan, many people with IBS can regain confidence and better control over their digestive health.

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