What Is Inflammatory Bowel Disease (IBD)?
Inflammatory bowel disease (IBD) is a group of chronic conditions in which the immune system causes persistent inflammation (ongoing irritation and swelling) in the digestive tract. This inflammation is not a temporary reaction to a bad meal or a passing stomach bug. It is a long-term process that can damage the lining of the bowel over time.
IBD is not the same as irritable bowel syndrome (IBS). IBS is a functional condition, meaning the bowel behaves differently without visible structural damage. IBD involves measurable inflammation that doctors can see and assess through investigations.
The two main types of IBD are:
- Crohn’s disease: Can affect any part of the digestive tract, from the mouth to the anus
- Ulcerative colitis: Affects only the large bowel (colon) and rectum
Both conditions follow a pattern of flare-ups (periods when symptoms worsen) and remission (periods when symptoms ease or disappear). IBD is a lifelong condition, but it can be managed with the right combination of medical care and monitoring.
How Is Crohn’s Disease Different from Ulcerative Colitis?
Crohn’s disease and ulcerative colitis are both forms of IBD, but they behave quite differently in the body. Ulcerative colitis is a continuous stretch of inflamed tissue confined to the large bowel, while Crohn’s disease presents as scattered patches of inflammation that can appear anywhere along the digestive tract and burrow deeper into the bowel wall.
| Feature | Crohn’s Disease | Ulcerative Colitis |
|---|---|---|
| Location of inflammation | Any part of the digestive tract (mouth to anus); most commonly the small bowel and colon | Large bowel (colon) and rectum only |
| Depth of inflammation | Can penetrate all layers of the bowel wall | Affects the innermost lining of the bowel only |
| Pattern of inflammation | Patchy (affected areas interspersed with healthy tissue) | Continuous (spreads in an unbroken pattern from the rectum upward) |
| Common symptoms | Abdominal pain, diarrhoea, weight loss, fatigue; may include mouth ulcers or perianal complications | Diarrhoea (often with blood or mucus), urgency, lower abdominal cramping |
| Common complications | Fistulas (abnormal connections between organs), strictures (narrowing of the bowel), abscesses | Toxic megacolon (dangerous bowel dilation), increased risk of colorectal cancer with long-standing disease |
Which type of IBD a person has can shape the medications a doctor may recommend, the monitoring schedule that may be needed, and whether surgery is likely to play a role in care. A healthcare professional can help determine the most appropriate approach based on individual circumstances.
Common Signs and Symptoms of IBD
IBD symptoms vary considerably from person to person and tend to fluctuate: they may intensify during a flare-up and ease during remission.
Digestive Symptoms
- Persistent diarrhoea: Loose or frequent stools that last for weeks rather than days
- Abdominal pain and cramping: Often in the lower abdomen, which may worsen before or after bowel movements
- Blood in the stool: Ranging from streaks of bright red blood to darker, mixed blood
- Urgency: A sudden, strong need to use the toilet that can be difficult to control
- Incomplete evacuation: A feeling that the bowel has not fully emptied after a visit to the toilet
- Mucus in the stool: Particularly common in ulcerative colitis
Symptoms Beyond the Gut
IBD is not limited to the digestive system. The chronic inflammation can affect other parts of the body:
- Fatigue: A persistent tiredness that does not improve with rest, often related to ongoing inflammation or anaemia (low red blood cell count)
- Unintended weight loss: Particularly in Crohn’s disease, where poor nutrient absorption may be a factor
- Fever: Low-grade fever during active flare-ups
- Joint pain or swelling: Affecting larger joints such as the knees or ankles
- Skin changes: Tender red bumps or rashes, most commonly on the legs
- Eye inflammation: Redness, pain, or sensitivity to light
What Causes IBD and Who Is at Risk?
The exact cause of IBD is not yet fully understood. Current research points to a complex interaction between the immune system, genetic factors, and environmental influences.
The Role of the Immune System
In a healthy digestive tract, the immune system protects the bowel lining from harmful bacteria while leaving beneficial gut bacteria undisturbed. In IBD, the immune system mistakenly attacks the bowel’s own tissue, triggering inflammation that does not resolve on its own. This immune dysregulation (a malfunction in how the immune system regulates itself) appears to be influenced by a combination of genetic susceptibility and environmental triggers, including certain infections, changes in gut bacteria, and possibly early-life exposures.
Having a close family member with IBD may increase your likelihood of developing it, though many people with IBD have no family history of the condition.
IBD in Singapore and Asia
IBD has traditionally been more common in Western countries, but its prevalence across Asia, including Singapore, has been rising. Researchers believe that urbanisation, dietary changes, and shifts in gut microbiome (the community of bacteria living in the digestive tract) may all play a role. Local gastroenterologists and colorectal surgeons are increasingly experienced in diagnosing and managing IBD.
How Is IBD Diagnosed?
Reaching an accurate diagnosis involves several steps. Your doctor will build a picture from your symptoms, examination findings, and a series of investigations.
Blood Tests and Stool Markers
Initial investigations typically include:
- Blood tests: To check for signs of inflammation (such as elevated C-reactive protein or erythrocyte sedimentation rate), anaemia, and nutritional deficiencies
- Stool tests: A faecal calprotectin test measures a protein released by white blood cells in an inflamed bowel. Elevated levels suggest intestinal inflammation and help distinguish IBD from IBS. Stool cultures may also be taken to rule out infection as a cause of symptoms.
Colonoscopy and Imaging
A colonoscopy is a camera examination of the large bowel. A thin, flexible tube with a small camera at its tip is gently passed through the rectum to allow the doctor to directly visualise the bowel lining, seeing areas of inflammation, ulceration, or abnormal tissue.
During a colonoscopy, small tissue samples (biopsies) are usually taken and sent to a laboratory for analysis. These biopsies can help confirm the diagnosis and assist in distinguishing between Crohn’s disease and ulcerative colitis.
For Crohn’s disease, which can affect the small bowel, additional imaging such as an MRI or CT scan may be used to map the extent of disease and identify complications such as strictures or fistulas.
Treatment Options for IBD
Your doctor will tailor a treatment plan based on which type of IBD you have, how severe it is, which part of the digestive tract is affected, and how your body responds to treatment over time.
Medications for Managing Inflammation
- Aminosalicylates (5-ASA drugs): Anti-inflammatory medications used primarily for mild to moderate ulcerative colitis to reduce inflammation in the bowel lining
- Corticosteroids: Used to bring active flare-ups under control. They are generally used short-term due to side effects with prolonged use
- Immunosuppressants: Medications such as azathioprine or methotrexate that reduce the immune system’s activity, helping to maintain remission and reduce the frequency of flare-ups
- Biologics: A class of medications that target specific proteins involved in the inflammatory process. Examples include anti-TNF agents and integrin inhibitors. Biologics are typically considered when other medications have not provided adequate control.
- Small molecule drugs (JAK inhibitors): Oral medications that work by blocking specific signalling pathways involved in inflammation, used in some cases of moderate to severe ulcerative colitis
When Surgery May Be Recommended
Surgery becomes an important option in several situations:
- Symptoms do not respond adequately to medication
- A complication develops, such as a bowel perforation, abscess, or fistula
- A stricture (narrowing of the bowel) causes an intestinal obstruction
- There is a risk of or confirmed colorectal cancer
In ulcerative colitis, surgical removal of the colon may address the colonic disease, though it involves a significant procedure and recovery.
Minimally Invasive Surgical Approaches for IBD
Laparoscopic surgery (keyhole surgery) involves making several small incisions rather than one large opening, allowing the surgeon to work with a camera and specialised instruments. Robotic-assisted surgery offers a similar approach with different technical characteristics.
For patients, these approaches may offer:
- Smaller incisions and less visible scarring
- Reduced post-operative pain
- Shorter hospital stays
- Support a quicker return to daily activities compared to open surgery
Not every patient or procedure is suitable for a minimally invasive approach, and your surgeon will discuss the most appropriate technique for your specific situation.
Living with IBD is a long-term journey
IBD is a chronic condition, but chronic does not mean unmanageable. With the right medical care, lifestyle adjustments, and regular monitoring, many people with IBD are able to maintain full and active lives.
How Patients Can Take an Active Role in Managing IBD
Practical steps you may consider include:
- Keep a symptom diary: Note when symptoms occur, how severe they are, and any potential triggers such as specific foods, stress, or illness.
- Identify your dietary triggers: Certain foods may worsen symptoms during a flare-up. Working with your doctor or a dietitian to identify personal triggers may be more helpful than following overly restrictive diets that could affect your nutrition.
- Attend regular follow-up appointments: IBD requires ongoing monitoring, even during periods of remission. Regular reviews allow your doctor to adjust your treatment plan and screen for complications.
- Communicate openly with your care team: Symptoms that are bothering you are worth discussing with your doctor.
When to Seek Professional Help
You may wish to speak with a doctor if you notice:
- Persistent diarrhoea lasting more than a few weeks
- Blood in your stool, whether bright red or dark
- Significant abdominal pain that does not resolve
- Unexplained weight loss over a short period
- Persistent fever without an obvious cause
If you have already been diagnosed with IBD, seeking a review may be helpful if:
- A flare-up is more severe or prolonged than usual
- New symptoms appear, such as perianal pain or swelling
- Your current medication no longer appears to be controlling your symptoms
Commonly Asked Questions
Is IBD the same as irritable bowel syndrome (IBS)?
No. IBD involves actual structural inflammation in the bowel, which doctors can see and measure through investigations such as colonoscopy and blood tests. IBS is a functional condition, meaning the bowel behaves differently (causing pain, bloating, or altered bowel habits) without visible inflammation or structural damage. Both are real and can significantly affect quality of life, but they require different approaches to diagnosis and management.
Can IBD be cured?
There is currently no cure for IBD. However, available treatments may help control inflammation, reduce the frequency and severity of flare-ups, and support quality of life. In ulcerative colitis, surgical removal of the colon may address the colonic disease, though this is a significant decision made in specific circumstances.
How long does IBD treatment take?
IBD management is typically lifelong. Treatment plans are adjusted over time based on how the condition behaves and how you respond to medication. During a flare-up, your doctor may temporarily adjust treatment to bring inflammation under control. During remission, medication may be reduced or maintained at a lower level to help prevent recurrence.
Does diet cause or worsen IBD?
Diet does not cause IBD. However, certain foods may trigger or worsen symptoms during a flare-up for some individuals. Foods that some people find problematic include high-fibre foods, dairy products, spicy foods, and alcohol, though triggers vary considerably from person to person. Working with your healthcare team to identify personal triggers and maintain adequate nutrition may be helpful.
What does IBD surgery involve and how long is the recovery?
IBD surgery typically involves removing a damaged or diseased section of the bowel, or in the case of ulcerative colitis, potentially the entire colon. Where suitable, minimally invasive techniques such as laparoscopic or robotic-assisted surgery may support shorter hospital stays and a return to daily activities compared with traditional open surgery. Recovery varies depending on the type of procedure and the individual patient. Your colorectal specialist will discuss what to expect in detail before any surgical decision is made.
