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Crohn's Disease (CD)

Name of disease:

Crohn's Disease (CD)

ICD-10 diagnosis code:



The exact cause of Crohn's disease is not known, but studies suggest that Crohn's disease may result from a combination of certain genetic variations, changes in the immune system, and the presence of bacteria in the digestive tract. Recent studies have found that variations in specific genes, including the ATG16L1, IL23R, IRGM, and NOD2 genes, influence the risk of developing Crohn's disease. These genes provide instructions for making proteins that are involved in immune system function. Variations in any of these genes may disrupt the ability of intestinal cells to respond to bacteria, leading to chronic inflammation and thus the signs and symptoms of the condition. There may also be genetic variations in regions of chromosome 5 and chromosome 10 that contribute to an increased risk to develop Crohn's disease.

Pattern of inheritance:

Crohn's disease, like most other autoimmune diseases, is thought to be a multifactorial condition. This means it is likely associated with the effects of multiple genes, in combination with lifestyle and environmental factors. Once an autoimmune disease is present in a family, other relatives may be at risk to develop the same autoimmune disease, or a different autoimmune disease. However, if an autoimmune disease such as Crohn's disease occurs in a family, it does not necessarily mean that relatives will develop an autoimmune disease.


The prevalence of CD has an incidence of 3 to 20 cases per 100,000.. Crohn disease is more common in the industrialized world, particularly in North America and Western Europe, though the incidence is rising in Asia and South America.


Physical examinations assess the signs and symptoms. More tests are done to distinguish Crohn's disease from other inflammatory bowel diseases including: Blood tests Tissue tests Ultrasound X-rays CT scan Endoscopy Genetic testing

Age of onset:

All age groups but mostly between age 15 and 35.

Common signs and symptoms:

Abdominal pain Cramping Diarrhea Weight loss Feeling tired Nausea Loss of appetite Fever Anemia Bowel obstruction Growth delay

Available treatments (medicinal and non-medicinal):

Surgery (removal of the diseased segment of bowel) Drug Treatment (e.g., Adalimumab, Infliximab)

Disease management tips:

It is recommended to take a Low Residue Diet to reduce the residue left in the gastrointestinal tract after digestion. Avoiding high-fiber foods and foods that are known to stimulate the gut, such as spicy foods.


Other useful websites:

Patient Groups: The Hong Kong Crohns and Colitis Societyhttps://www.facebook.com/ccs.org.hk Inflammatory Bowel Disease Patient Group (Taiwan)https://www.ibdpg.tw/tw