Crohn’s Disease

What Is Crohn’s Disease?

Crohn's disease is a chronic condition that causes inflammation in any part of the gastrointestinal tract, from the mouth to the anus. It commonly affects the small intestine and the beginning of the large intestine. It is a type of inflammatory bowel disease (IBD).

Crohn's disease is characterised by periods of flare-ups, where symptoms worsen, followed by periods of remission, where symptoms improve or disappear. It typically requires lifelong management and can significantly impact a person's quality of life.

Types of Crohn’s Disease

Crohn's disease presents in five main types, each characterised by inflammation in different parts of the gastrointestinal tract. These types include:


Inflammation occurs at the end of the small intestine (ileum) and extends to a portion of the large intestine (colon).


Inflammation affects the last section of the small intestine (ileum).

Crohn's (Granulomatous) Colitis

Inflammation is limited to the colon.

Gastroduodenal Crohn’s

Inflammation involves the stomach and the beginning of the small intestine (duodenum).


Inflammation occurs in the middle part of the small intestine (jejunum).

Risk Factors for Crohn’s Disease

Several factors can increase the risk of developing Crohn's disease, including:

Family History

Having a parent, child, or sibling with the disease increases the risk of developing Crohn's disease.


Tobacco use is linked to an increased risk, as well as more severe symptoms and a higher likelihood of needing surgery.

Environmental Factors

Factors such as microbiota, microorganisms, stress, and diet have been associated with the risk of developing Crohn's disease.


While Crohn's disease can occur at any age, most cases are diagnosed in early adulthood.


Certain medications have been identified as potential risk factors for developing Crohn's disease.

Signs and Symptoms of Crohn’s Disease

The symptoms of Crohn's disease can manifest gradually or suddenly, ranging from mild to severe. Common ones include:


Persistent or recurring diarrhoea, which may be bloody in some cases

Abdominal Pain and Cramping

Often located in the lower right side of the abdomen

Weight Loss

Unintentional weight loss due to decreased appetite and malabsorption of nutrients


Generalised fatigue and weakness, possibly due to anaemia or the systemic effects of chronic inflammation


Low-grade fever, especially during flare-ups of the disease

Perianal Disease

Inflammation around the anus, leading to pain, drainage, abscesses, and fistulas

Reduced Appetite

Loss of appetite or feeling full quickly, potentially contributing to weight loss

Nausea and Vomiting

Common symptoms, especially during active disease periods

Joint Pain

Inflammation in the joints, resulting in pain and discomfort

How Is Crohn’s Disease Diagnosed?

Doctors initially conduct a thorough physical examination to assess symptoms and signs of Crohn's disease. They may also require additional tests before confirming the diagnosis. These tests include:

Blood Tests

Blood tests may be ordered to check for anaemia, infection, inflammation, and other indicators of disease activity.

Stool Sample Analysis

Examination of a stool sample can help rule out other causes of gastrointestinal symptoms, such as infections or malabsorption issues.


This procedure allows the doctor to examine the entire colon and the end of the small intestine (terminal ileum) using a flexible tube with a camera.

Imaging Studies

CT scans, MRI, and capsule endoscopy may be used to visualise the digestive tract and assess the extent and severity of inflammation.

Treatments for Crohn’s Disease

Treatment options for Crohn’s disease are tailored to each individual, focusing on reducing inflammation, preventing complications, and promoting long-term remission.

Dietary Adjustments

Dietary adjustments may include avoiding certain foods like carbonated drinks, high-fibre items, and nuts while increasing fluid intake and eating smaller, more frequent meals. Keeping a food diary can help identify trigger foods. Some people may benefit from specialised diets, such as high-calorie, lactose-free, low-fat, low-fibre, or low-salt diets.


Treatment for Crohn's disease typically involves medication aimed at reducing inflammation, often by suppressing the immune system. Nonsteroidal anti-inflammatory drugs and anti-diarrheal medicines can help manage symptoms and complications. Additionally, antibiotics may be necessary if an infection occurs.

Bowel Rest

In severe cases, bowel rest may be recommended, involving the consumption of only certain liquids or no food or drink at all to allow the intestines to rest. This can be done at home or in the hospital and may last from a few days to several weeks.


Surgery becomes an option when other treatments fail to provide sufficient relief. It may involve removing damaged sections of the digestive tract to address complications like fistulas, life-threatening bleeding, obstructions, or severe side effects from medications.

Complications of Crohn’s Disease

Crohn's disease can lead to various complications, such as:

Bowel Obstruction

Crohn's disease can cause a narrowing of the intestines, leading to blockages and severe abdominal pain.


Inflammation in the digestive tract can result in the formation of ulcers, which may lead to bleeding or perforation.


Abnormal connections between different parts of the intestine or between the intestine and other organs, potentially leading to infections or abscesses.

Anal Fissures

Tears or cracks in the lining of the anus, causing pain and bleeding during bowel movements.


Difficulty absorbing nutrients due to inflammation or damage to the intestines, leading to weight loss and nutritional deficiencies.

Thromboembolic Disease

Crohn's disease can increase the risk of conditions such as deep vein thrombosis, stroke, or pulmonary embolism.

Frequently Asked Questions (FAQs)

Is there a cure for Crohn’s disease?

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How common is Crohn’s disease?

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Will I require surgery for Crohn’s disease?

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How can I manage pregnancy with Crohn’s disease?

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Meet Our Specialist

Dr Kieron Lim

MBBS, University of LondonMember, Royal College of Physicians (UK)Fellow, Academy of Medicine (Gastroenterology) SingaporeFellow, Royal College of Physicians (Edinburgh)

Dr Kieron Lim is a senior consultant specialising in Gastroenterology and Hepatology at Mount Elizabeth Hospital. He is currently the President-Elect of the Gastroenterological Society of Singapore (GESS) and previously served as the Chairman of the Gastroenterology Special Interest Group and Endoscopy Committee at Mount Elizabeth Hospital. Dr Lim's expertise covers treating conditions throughout the gastrointestinal tract, including the management of chronic and debilitating conditions like Crohn’s disease. Dr Lim strives to improve his patients’ quality of lives through supportive and comprehensive care.