Inflammatory Bowel Disease (IBD)

Digestive discomfort is common, but when symptoms such as persistent diarrhoea, abdominal pain or unexplained fatigue continue for weeks or months, it may signal an underlying inflammatory condition affecting the intestines.

One possible cause is Inflammatory Bowel Disease (IBD), a group of long-term conditions characterised by inflammation of the digestive tract. Unlike temporary digestive disturbances, IBD involves ongoing immune-driven inflammation that can damage the intestinal lining over time.

In Singapore and across Asia, the number of people diagnosed with IBD has been increasing steadily. Studies suggest that incidence rates in Asia have risen several-fold over the past two decades, reflecting both improved awareness and changing environmental and lifestyle factors.

Although IBD is a chronic condition, early diagnosis and appropriate treatment can significantly improve symptom control and reduce complications.

What is Inflammatory Bowel Disease?

Inflammatory bowel disease refers to a group of conditions that cause chronic inflammation within the gastrointestinal tract.

This inflammation occurs when the body’s immune system mistakenly attacks the lining of the digestive tract. Over time, the persistent inflammatory response can damage intestinal tissue, leading to ulcers, bleeding and digestive symptoms.

Symptoms often occur in periods of flare-ups and remission, meaning patients may experience phases of active symptoms followed by periods of relative stability. Because inflammation can affect different areas of the digestive tract, symptoms and complications may vary depending on the specific type of IBD.

Types of Inflammatory Bowel Disease

The two most common forms of IBD are Crohn's disease and Ulcerative colitis, which are:

• Crohn’s Disease – the condition can affect any part of the digestive tract, from the mouth to the anus, although it most commonly involves the small intestine and the beginning of the large intestine. Inflammation in Crohn’s disease often extends through multiple layers of the intestinal wall, which can lead to complications such as strictures, fistulas or abscesses.
• Ulcerative Colitis – this primarily affects the large intestine and rectum. Inflammation typically involves the inner lining of the colon, causing ulcers that may lead to bleeding, diarrhoea and abdominal discomfort.

Although both conditions share similarities, their patterns of inflammation and long-term management strategies differ.

What is the difference between IBD and IBS?

Inflammatory bowel disease is sometimes confused with Irritable Bowel Syndrome (IBS) because both conditions can cause abdominal pain and changes in bowel habits. However, they are fundamentally different.

IBD involves visible inflammation and structural damage to the digestive tract. It can lead to complications such as ulcers, bleeding, strictures and nutritional deficiencies if it is left untreated. IBS, in contrast, is a functional disorder that affects how the bowel works. It does not cause inflammation, intestinal damage or long-term complications.

What causes Inflammatory Bowel Disease?

The exact cause of IBD remains unclear, but research suggests that several factors interact to trigger the disease. This includes:

• Immune system dysregulation – in IBD, the immune system mistakenly attacks the intestinal lining, leading to chronic inflammation.
• Gut microbiome imbalance – changes in the balance of bacteria within the digestive tract may influence inflammation and immune responses.
• Environmental influences – urbanisation, diet changes and environmental exposures have been associated with rising IBD rates in Asia.
  Genetics — there are over 200 genetic loci identified as associated with IBD risk. Having a first-degree relative with IBD significantly increases your risk. Certain gene variants affect how the immune system responds to gut bacteria, which is why genetics and immune function are closely linked in IBD.

What are the common symptoms of Inflammatory Bowel Disease?

Symptoms of IBD vary depending on the affected area and severity of inflammation, but often include:

• Persistent diarrhoea
• Abdominal pain or cramping
• Blood or mucus in the stool
• Unexplained weight loss
• Fatigue or reduced energy levels
• Urgency to pass stool

Some individuals may also experience symptoms outside the digestive system, such as joint pain, skin inflammation or eye irritation.

Does blood in my stool always mean IBD?

Not necessarily. Blood in stool has many possible causes, most of which are unrelated to IBD — including haemorrhoids, anal fissures, polyps or colorectal cancer. That said, blood is a common feature of IBD, particularly ulcerative colitis, where it often appears mixed with mucus. In Crohn's disease, bleeding is less consistent and depends on where the inflammation is located.

The colour can offer some clues. Bright red blood usually points to a lower GI source such as the rectum or sigmoid colon, while dark or tarry stools suggest bleeding higher up. But none of this is diagnostic on its own.

Blood in stool is never normal and should always be assessed by a doctor.

Who is at risk of developing Inflammatory Bowel Disease?

There are certain factors that may increase the risk of developing IBD. These include:

• Younger age groups – many patients are typically diagnosed between 13 and 30 years old. This period of life is when immune system regulation and genetic susceptibility may interact with environmental triggers, allowing the disease to first manifest.
• Family history – individuals with relatives affected by IBD may have a higher genetic susceptibility. Certain inherited genetic variations may influence how the immune system responds to bacteria in the digestive tract, increasing the tendency for abnormal intestinal inflammation.
• Urban living environments – higher rates of IBD have been observed in urbanised regions, including parts of Singapore and East Asia. Environmental factors associated with city living, such as reduced exposure to certain microbes, dietary changes and lifestyle patterns, may influence gut bacteria and immune responses, contributing to the development of IBD.
• Dietary and lifestyle factors – diets that are higher in processed foods, refined sugars and saturated fats may affect the balance of bacteria in the gut. These changes in the intestinal microbiome can alter immune responses in the digestive tract, potentially increasing the risk of chronic inflammation.
• Smoking – smoking has been associated with an increased risk of Crohn’s disease. It may alter blood flow in the intestinal lining and influence immune activity, which can worsen inflammation and increase the likelihood of disease complications.

What complications can Inflammatory Bowel Disease cause?

If inflammation remains uncontrolled, IBD may lead to complications affecting the digestive tract and other parts of the body, such as:

• Intestinal strictures – chronic inflammation may cause narrowing of the bowel.
• Fistulas – abnormal tunnels can form between sections of the intestine or nearby organs.
• Abscess formation – pockets of infection may develop near inflamed areas.
• Malnutrition – poor nutrient absorption can lead to deficiencies and weight loss.
• Increased colorectal cancer risk – long-standing inflammation of the colon may increase cancer risk.

How is Inflammatory Bowel Disease diagnosed in Singapore?

Diagnosing IBD requires confirming the presence of intestinal inflammation and identifying its location. The investigations may involve:

• Medical history and symptom assessment – Dr Aaron Poh evaluates symptom patterns, duration and severity to understand the extent of the condition.
• Blood tests – these help detect signs of inflammation, infection or anaemia.
• Stool tests – stool analysis can identify inflammatory markers and rule out infections.
• Colonoscopy with biopsy – a colonoscopy allows direct visualisation of the colon and rectum. Small tissue samples may be taken to confirm inflammation and determine the type of IBD.
• Imaging studies – Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scans may be used to assess deeper sections of the intestine, particularly in Crohn’s disease.

What are the treatment options for Inflammatory Bowel Disease in Singapore?

Management of IBD focuses on reducing inflammation, controlling symptoms and preventing disease progression.

• Anti-inflammatory medications – these medications reduce inflammation in the intestinal lining and are often used as first-line therapy in mild to moderate disease.
• Immune system modulators – these treatments suppress abnormal immune activity that drives inflammation in IBD. They are often used when symptoms persist despite initial therapy.
• Biologic therapy – biologic medications target specific molecules involved in the inflammatory process. They are commonly used in moderate to severe disease to achieve long-term control.
• Surgical treatment – surgery may be necessary when complications occur, such as intestinal narrowing, severe bleeding or disease that does not respond to medication. In ulcerative colitis, removing the colon can sometimes provide definitive disease control.
• Nutritional and supportive care – dietary adjustments and nutritional support may help manage symptoms and prevent deficiencies during flare-ups.

How a Colorectal Specialist can help

Inflammatory bowel disease requires long-term monitoring because symptoms and disease activity can change over time.

A colorectal specialist evaluates the extent of inflammation, monitors disease progression and helps determine when treatment adjustments are needed. This includes coordinating investigations, assessing treatment response and identifying complications early.

With appropriate medical management and regular follow-up, many individuals with IBD can maintain stable disease control and continue their daily activities with fewer disruptions.

If you have been experiencing IBD-related symptoms, schedule a consultation with Dr Aaron Poh for a detailed diagnosis and personalised treatment plan.

Frequently Asked Questions