Understanding Irritable Bowel Syndrome (IBS): Symptoms, Causes, and Diagnosis
If you’re living with Irritable Bowel Syndrome IBS, you’ve likely experienced how confusing and frustrating it can be. The symptoms can come and go unpredictably, and it often feels like no matter what you do, nothing provides lasting relief. I’m here to break down what IBS is and how it’s diagnosed—so you can gain clarity and start your journey toward better health.
What Is IBS?
IBS is a disorder of gut brain interaction, which means there’s no visible change to your gut or digestive system, but that doesn’t make the symptoms any less real.
IBS is a problem with how your gut and brain communicate, which generates problems with gut function, sensitivity and motility.
For years, it was thought IBS was purely a disorder of the lower gastrointestinal (GI) tract, where the symptoms typically focused on the colon and intestines. But now we understand that disruptions in gut-brain communication can also affect the upper GI tract, triggering symptoms like acid reflux, heartburn, and upper abdominal discomfort. The idea that IBS is just a "colon issue" has evolved.
IBS is often categorised by the types of symptoms people experience:
IBS-D (diarrhoea-predominant)
IBS-C (constipation-predominant)
IBS-M (mixed, with both diarrhoea and constipation)
IBS doesn’t cause damage to your intestines, but the symptoms can take a toll on your daily life. And while it’s incredibly common, affecting millions of people worldwide, it’s still often misunderstood. Let’s get into the symptoms you might be experiencing.
Common IBS Symptoms
IBS symptoms can vary widely from person to person-
Abdominal pain or cramping: This is one of the most common symptoms, often improving after a bowel movement.
Bloating: Many people with IBS feel constantly bloated, even if they haven’t eaten much.
Gas: IBS can lead to increased gas production, contributing to the bloating and discomfort.
Changes in bowel habits: You may experience diarrhoea, constipation, or alternating between both. Some people feel an urgent need to go, while others struggle to go at all or have a feeling of incomplete evacuation after a bowel movement.
Mucus in stool: You might have increased mucus production.
Non-Colonic Symptoms of IBS: It's More Than Just the Gut
IBS also presents with non-colonic symptoms, which means the impact goes beyond your digestive system. Many people experience nausea, fatigue, and even sleep disturbances. These symptoms are often the result of the same gut-brain dysregulation that causes digestive issues.
Nausea: Disruption of the gut-brain connection and Increased stress and anxiety, can lead to sensations of nausea.
Fatigue: Living with IBS can be exhausting, both physically and emotionally. The constant discomfort, bloating, and digestive issues take a toll, and many people with IBS report feeling fatigued, even after a full night’s sleep.
IBS affects your entire wellbeing, which is why a holistic approach to managing it is so important.
What Causes IBS?
While the exact cause of Irritable Bowel Syndrome (IBS) isn’t fully understood, research points to several factors that can disrupt the gut-brain axis, leading to IBS symptoms. It’s likely a combination of these factors, and the impact can vary depending on the individual.
Stress
Stress plays a major role in disrupting the gut-brain connection. The communication between the brain and the gut is particularly sensitive to stress, and for many people with IBS, high stress levels can lead to significant flare-ups. Stress impacts the autonomic nervous system, which can lead to altered gut function, causing cramping, bloating, and changes in bowel habits. Over time, chronic stress can dysregulate the gut-brain axis, leading to long-term IBS symptoms.
Gut Microbiome Imbalance
The bacteria in your gut, known as the gut microbiome, are critical for maintaining digestive health. In people with IBS, there’s often an imbalance in this microbial environment, which can negatively affect the gut-brain axis. An imbalance in gut bacteria can lead to inflammation, altered gut motility, and increased gut sensitivity—all of which contribute to IBS. Research has shown that a disrupted microbiome can send incorrect signals to the brain, leading to changes in gut function.
Post-Infectious IBS (Infections or Inflammation)
In some cases, IBS develops after a severe digestive infection, such as gastroenteritis. This is known as post-infectious IBS. It is thought that the infection alters the gut’s immune response and the gut-brain communication, leading to chronic digestive issues even after the infection has cleared. The immune changes and resulting inflammation can disrupt normal gut function, further affecting the gut-brain axis.
Early Life Trauma
Research has shown that early life trauma, such as abuse, neglect, or significant emotional stress during childhood, can have a lasting impact on the gut-brain axis. The gut-brain connection is shaped early in life, and trauma can alter the development of this system. This disruption can increase the likelihood of experiencing gut sensitivity, abnormal gut motility, and heightened stress responses later in life, all of which contribute to IBS.
Genetic Predisposition
There is evidence to suggest that a genetic predisposition may make some individuals more susceptible to IBS. While no single gene causes IBS, certain genetic factors may contribute to an individual’s gut sensitivity or how their brain responds to gut signals. This genetic influence, combined with environmental factors like stress or infection, can disrupt the gut-brain axis and lead to the development of IBS.
Understanding the Gut-Brain Axis
These factors—stress, microbiome imbalances, post-infectious changes, early life trauma, and genetic predisposition—disrupt the delicate gut-brain axis, which is the communication system between your gut and brain. When this system is out of balance, the gut can become hypersensitive, leading to the classic IBS symptoms of pain, bloating, and altered bowel habits.
How Is IBS Diagnosed?
One of the most challenging parts of dealing with IBS is getting a clear diagnosis. Since there’s no single test for IBS, the diagnosis is typically made by ruling out other conditions that might be causing your symptoms. Here’s how the process usually works:
Medical History and Symptom Review
The first step in diagnosing IBS is a thorough review of your symptoms and medical history. Your healthcare provider will ask about the frequency and nature of your symptoms, whether you’ve noticed any triggers, and how long you’ve been dealing with them. They’ll also want to know if anyone in your family has had similar issues, as digestive disorders can sometimes run in families.
Physical Exam
Your doctor may perform a physical exam to check for any tenderness in your abdomen or signs of other digestive problems. While this might not be able to definitively diagnose IBS, it helps rule out other conditions.
Tests to Rule Out Other Conditions
To confirm IBS, your doctor might recommend some tests to exclude other conditions with similar symptoms. These could include:
Blood tests: To check for anaemia, celiac disease, or inflammation.
Stool tests: To look for signs of infection or inflammation.
Colonoscopy or endoscopy: In some cases, your doctor may recommend one of these tests to rule out inflammatory bowel disease (IBD) or other structural issues.
Rome IV Criteria
Doctors often use something called the Rome IV criteria to help diagnose IBS. This includes experiencing abdominal pain for at least one day a week over the past three months, along with changes in stool frequency or form. If your symptoms fit these criteria and other conditions have been ruled out, you’re likely to receive a diagnosis of IBS.
If you’re living with IBS, I know it can feel overwhelming and isolating at times. But understanding the causes and getting a clear diagnosis is the first step toward relief. IBS is a complex condition, but you don’t have to manage it on your own.