Crohn's disease is more common in people who have family members with the disease, which indicates the role genes may play in a person developing the condition. However, the majority of people who have Crohn's disease do not have a family history of the disease.
Smoking has been demonstrated to double the risk of Crohn’s disease. A diet high in fatty foods and low in fibre may also play a role in the development of Crohn’s disease, while some people find that specific foods affect their symptoms.
Signs and symptoms
Symptoms depend on where in the digestive tract the inflammation is happening, and its severity. Crohn’s is a lifelong condition that typically involves flare-ups followed by periods of remission where symptoms do not occur.
The main symptoms of Crohn’s disease are chronic diarrhoea and abdominal pain. Other symptoms include:
- Rectal bleeding
- Weight loss, and loss of appetite
- Nausea, vomiting
- Malnutrition and vitamin deficiencies
- Tiredness, lethargy
- Bone loss (osteoporosis)
- Depression, anxiety (associated with coping with the condition)
- Stunted growth in children (which may occur many years before digestive symptoms appear).
Crohn's disease may also lead to ulcers in the digestive tract and it increases the risk of bowel cancer.
A doctor may suspect Crohn's disease or ulcerative colitis in a person who has had abdominal pain, diarrhoea, and weight loss over a period of weeks or months (reaching a diagnosis of one or the other is important because the two conditions are treated differently).
Blood tests may be done to look for a low blood count (anaemia, may result from rectal bleeding), measure the severity of inflammation, and detect vitamin or mineral deficiencies. A bowel motion specimen (poo sample) may be needed to test for blood and exclude infection as the cause of the symptoms being experienced.
Most people will need part of their intestine to be examined, either by direct or indirect inspection. Direct inspection is done using a small flexible tube (endoscope) with a fibre-optic camera at its tip which is inserted through the anus (this procedure is known as a colonoscopy or sigmoidoscopy) or through the mouth (gastroscopy).
The doctor is able to see sections of the digestive tract on a television screen and can look for signs of inflammation that may indicate Crohn’s disease. Small samples (biopsies) of the lining of digestive tract may be taken for analysis in a laboratory.
Indirect inspection involves the use of computerised tomography (CT) scan or barium x-rays. In the latter procedure, barium liquid is swallowed or injected into the rectum to enhance what can be seen in the x-ray images.
There is no cure for Crohn’s disease. The primary goals of treatment are:
- To achieve the best possible control of the inflammation with the fewest adverse effects from medication
- To permit life to be lived as normally as possible
- In children, to promote growth with adequate nutrition.
Because Crohn’s disease is a lifelong condition, many people will need to take medications for extended periods of time to bring the disease under control and then prevent symptoms from flaring up again.
A combination of medications is often required. The choice of medications used depends on the location of the inflammation, the severity of symptoms, and whether the aim is to treat a flare-up or to prevent further flare-ups. The types of side effects experienced, which can vary for different people, may also be a factor in the choice of medication used.
Four main categories of medication are used to treat inflammation in Crohn’s disease:
- Medications that reduce inflammation. They can be taken by mouth (orally) and into the rectum (as an enema or suppository).
- Medications that suppress the immune system
- Antibiotics that are thought to work by altering the bacterial population in the intestine
- Antibody-based medications that disrupt the inflammation process.
Major surgery, called resection, may be needed to remove severely inflamed or damaged portions of the small or large intestines. Abscesses or fistulae around the anus can be treated using local surgical drainage procedures.
People can be free of disease and symptoms for some time, often years, after a resection, and enjoy a marked improvement in their quality of life. In many people, however, Crohn's disease eventually returns, affecting previously healthy digestive tract. Half of patients can expect to have a recurrence of symptoms within four years of surgery.
A well-balanced and nutritious diet is essential for anyone with Crohn’s disease to prevent malnutrition and maintain good health. A healthy diet is even more important for growing children and adolescents with Crohn’s disease because without adequate nutrition they may experience delayed growth or puberty. Vitamin and mineral supplements might be necessary in some people. Fibre supplementation may be beneficial in some people with Crohn’s disease — dietary fibre helps the healing of inflamed regions of the digestive tract.
There is no specific Crohn’s disease diet that is recommended for all people, but people with the disease are likely to know some foods make their symptoms worse. Some people find that eating smaller portions at mealtimes helps to lessen some symptoms.
In a of study of Caucasian New Zealanders with Crohn’s disease, foods most often considered to be beneficial for symptoms included white fish, salmon and tuna, gluten-free products, and boiled potatoes and sweet potatoes. Foods most often considered to make symptoms worse included grapefruit, nuts, chilli or chilli sauce, cream, salami, energy drinks, and beer.
Crohn’s & Colitis New Zealand
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Updated: July 2020