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What is Crohn's disease?
Crohn's disease is an inflammatory bowel disease (IBD). It causes inflammation of your digestive tract. In Crohn's disease the inflammation often spreads deep into all the layers of bowel and can affect any part of the bowel and involve different areas of the digestive tract in different patients. This can lead to abdominal pain, severe diarrhoea, fatigue, weight loss, malnutrition and sometimes even serious life threatening complications.
While there's no known cure for Crohn's disease, therapies can greatly reduce its signs and symptoms and even bring about long-term remission. With treatment, many people with Crohn's disease are able to function well.
What are the symptoms?
The most common areas affected by Crohn's disease are the last part of the small intestine and the colon. In some people with Crohn's disease, only the last segment of the small intestine (ileum) is affected. In others, the disease is confined to the colon. However some, amy have widespread or patchy disease. Sign and symptoms vary according the part of the bowel affected and how severe the inflammation is.
Signs and symptoms of Crohn's disease can range from mild to severe. They usually develop gradually, but sometimes will come on suddenly, without warning. Sometimes there are periods of time when there are no signs or symptoms (remission).
When the disease is active, signs and symptoms may include:
- Abdominal pain and cramping
- Blood in your stool
- Mouth sores
- Reduced appetite and weight loss
- Pain or drainage near or around the anus due to inflammation from a tunnel into the skin (fistula)
Other signs and symptoms
People with severe Crohn's disease also may experience:
- Inflammation of skin, eyes and joints
- Inflammation of the liver or bile ducts
- Delayed growth or sexual development, in children
What causes the Crohn’s disease?
The exact cause of Crohn's disease remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but don't cause Crohn's disease. A number of factors, such as heredity and a malfunctioning immune system, likely play a role in its development.
It's possible that a virus or bacterium may trigger Crohn's disease. When your immune system tries to fight off the invading microorganism, an abnormal immune response causes the immune system to attack the cells in the digestive tract, too. Crohn's is more common in people who have family members with the disease. As many as 1 in 5 people with Crohn's disease has a family member with the disease, so genes may play a role in making people more susceptible. However, most people with Crohn's disease don't have a family history of the disease.
Crohn's disease can occur at any age, but you're likely to develop the condition when you're young. Most people who develop Crohn's disease are diagnosed before they're around 30 years old.
Cigarette smoking is the most important controllable risk factor for developing Crohn's disease. Smoking also leads to more-severe disease and a greater risk of having surgery. If you smoke, it's important to stop.
Nonsteroidal anti-inflammatory medications. These include ibuprofen (brufen), naproxen, diclofenac (Voltaren) and others. While they do not cause Crohn's disease, they can lead to inflammation of the bowel that makes Crohn's disease worse.
What are the possible complications?
Crohn's disease affects the thickness of the intestinal wall. Over time, parts of the bowel can scar and narrow, which may block the flow of digestive contents. You may require surgery to remove the diseased portion of your bowel.
Chronic inflammation can lead to open sores (ulcers) anywhere in your digestive tract, including your mouth and anus, and in the genital area (perineum).
Crohn's disease affects the full thickness of the intestinal wall. Sometimes this leads to deep ulcers in the bowel which eventually perforate and leak causing peritonitis. You may require surgery to control the leak and to remove the diseased portion of your bowel.
Sometimes ulcers can extend completely through the intestinal wall, creating a fistula — an abnormal connection between different body parts. Fistulas can develop between your intestine and skin, or between your intestine and another organ. Fistulas near or around the anal area (perianal) are the most common kind.
When fistulas develop in the abdomen, food may bypass areas of the bowel that are necessary for absorption. Fistulas may occur between loops of bowel, into the bladder or vagina, or out through the skin, causing continuous drainage of bowel contents to your skin.
In some cases, a fistula may become infected and form an abscess, which can be life-threatening if not treated.
This is a small tear in the tissue that lines the anus or in the skin around the anus where infections can occur. It's often associated with painful bowel movements and may lead to a perianal fistula.
Diarrhoea, abdominal pain and cramping may make it difficult for you to eat or for your intestine to absorb enough nutrients to keep you nourished. It's also common to develop anaemia due to low iron or vitamin B-12 caused by the disease.
Having Crohn's disease that affects your colon increases your risk of colon cancer. General colon cancer screening guidelines for people without Crohn's disease call for a colonoscopy every 10 years beginning at age 50. Ask your doctor whether you need to have this test done sooner and more frequently.
Other health problems
Crohn's disease can cause problems in other parts of the body. Among these problems are anaemia, skin disorders, osteoporosis, arthritis, and gallbladder or liver disease.
Certain Crohn's disease drugs that act by blocking functions of the immune system are associated with a small risk of developing cancers such as lymphoma and skin cancers. They also increase risk of infection.
Corticosteroids can be associated with a risk of osteoporosis, bone fractures, cataracts, glaucoma, diabetes and high blood pressure, among others. Work with your doctor to determine risks and benefits of medications.
How is it diagnosed?
This usually require a histological assessment of the diseases part of the bowel which can be obtained through a biopsy during endoscopy or during surgical excision of a diseased segment of the bowel which may confirm a diagnosis. Clusters of inflammatory cells called granulomas, if present, help confirm the diagnosis of Crohn's.
This test allows your doctor to view your entire colon and the very end of your ileum (terminal ileum) using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for histological analysis.
Computerised tomography (CT)
This test looks at the entire bowel as well as at tissues outside the bowel. CT enterography is a special CT scan that provides better images of the small bowel. This will estimate the disease involvement of the entire bowel.
Magnetic resonance imaging (MRI)
MRI is particularly useful for evaluating a fistula around the anal area (pelvic MRI) or the small intestine (MR enterography).
For this test, a scope is used in conjunction with a device called an overtube. This enables the doctor to look further into the small bowel where standard endoscopes don't reach. This technique is useful when the diagnosis is still in question.
What treatments are available?
There is currently no cure for Crohn's disease, and there is no one treatment that works for everyone. The goal of medical treatment is to reduce the inflammation that triggers your signs and symptoms. It is also to improve long-term prognosis by limiting complications. In the best cases, this may lead not only to symptom relief but also to long-term remission.
Anti-inflammatory drugs are often the first step in the treatment of inflammatory bowel disease. They include:
Corticosteroids: Corticosteroids such as prednisone and budesonide can help reduce inflammation in your body, but they don't work for everyone with Crohn's disease. Doctors generally use them only if you don't respond to other treatments. Corticosteroids may be used for short-term (three to four months) symptom improvement and to induce remission. Corticosteroids may also be used in combination with an immune system suppressor.
Oral 5-aminosalicylates: These drugs include sulfasalazine, which contains sulfa, and mesalamine. Oral 5-aminosalicylates have been widely used in the past but now are generally considered of limited benefit.
Immune system suppressors
These drugs also reduce inflammation, but they target your immune system, which produces the substances that cause inflammation. For some people, a combination of these drugs works better than one drug alone. Immunosuppressant drugs include:
Azathioprine (Imuran) and mercaptopurine: These are the most widely used immunosuppressants for treatment of inflammatory bowel disease. Taking them requires that you follow up closely with your doctor and have your blood checked regularly to look for side effects, such as a lowered resistance to infection and inflammation of the liver. They may also cause nausea and vomiting.
Methotrexate: This drug is sometimes used for people with Crohn's disease who don't respond well to other medications. You will need to be followed closely for side effects.
Biologics (Infliximab, Adalimumab, Certolizumab, Natalizumab, Vedolizumab, Ustekinumab): These drugs work by stopping certain immune molecules. Infliximab (Remicade), adalimumab (Humira) and certolizumab pegol (Cimzia) are called TNF inhibitors or biologics and they work by neutralizing an immune system protein known as tumor necrosis factor (TNF). Natalizumab and Vedolizumab work by stopping certain immune cell molecules — integrins — from binding to other cells in your intestinal lining. Vedolizumab recently was approved for Crohn's disease. Ustekinumab (Stelara) is used to treat psoriasis. Studies have shown that it's useful in treating Crohn's disease as well and may be used when other medical treatments fail.
Antibiotics: Antibiotics can reduce the amount of drainage and sometimes heal fistulas and abscesses in people with Crohn's disease. Some researchers also think antibiotics help reduce harmful intestinal bacteria that may play a role in activating the intestinal immune system, leading to inflammation. Frequently prescribed antibiotics include ciprofloxacin (Cipro) and metronidazole (Flagyl).
Anti-diarrhoeals: A fiber supplement can help relieve mild to moderate diarrhoea by adding bulk to your stool. For more severe diarrhoea, loperamide (Imodium) may be effective.
Pain relievers: For mild pain, your doctor may recommend paracetamol — but not other common pain relievers, such as ibuprofen, naproxen sodium. These drugs are likely to make your symptoms worse, and can make your disease worse as well.
Iron supplements: If you have chronic intestinal bleeding, you may develop iron deficiency anaemia and need to take iron supplements.
Vitamin B-12 shots: Crohn's disease can cause vitamin B-12 deficiency. Vitamin B-12 helps prevent anaemia, promotes normal growth and development, and is essential for proper nerve function.
Calcium and vitamin D supplements: Crohn's disease and steroids used to treat it can increase your risk of osteoporosis, so you may need to take a calcium supplement with added vitamin D.
Special diets: Your doctor may recommend a special diet given via a feeding tube (enteral nutrition) or nutrients injected into a vein (parenteral nutrition) to treat your Crohn's disease. This can improve your overall nutrition and allow the bowel to rest. Bowel rest can reduce inflammation in the short term. Enteral and parenteral nutrition are typically used to get people healthier prior to surgery or when other medications fail to control symptoms. A low residue or low-fiber diet to reduce the risk of intestinal blockage if you have a narrowed bowel (stricture).
If diet and lifestyle changes, drug therapy, or other treatments don't relieve your signs and symptoms, your doctor may recommend surgery. Nearly half of those with Crohn's disease will require at least one surgery. However, surgery does not cure Crohn's disease. During surgery, your surgeon removes a damaged portion of your digestive tract and then reconnects the healthy sections. Surgery may also be used to close fistulas and drain abscesses. The benefits of surgery for Crohn's disease are usually temporary. The disease often recurs, frequently near the reconnected tissue. The best approach is to follow surgery with medication to minimise the risk of recurrence.
Lifestyle and home remedies
Sometimes changes in your diet and lifestyle may help control your symptoms and lengthen the time between flare-ups. There's no firm evidence that what you eat actually causes inflammatory bowel disease. But certain foods and beverages can aggravate your signs and symptoms, especially during a flare-up. It can be helpful to keep a food diary to keep track of what you're eating, as well as how you feel. If you discover some foods are causing your symptoms to flare, you can try eliminating them. Here are some suggestions that may help:
Limit dairy products: Many people with inflammatory bowel disease find that problems such as diarrhoea, abdominal pain and gas improve by limiting or eliminating dairy products. You may be lactose intolerant — that is, your body can't digest the milk sugar (lactose) in dairy foods.
Try low-fat foods: If you have Crohn's disease of the small intestine, you may not be able to digest or absorb fat normally. Instead, fat passes through your intestine, making your diarrhoea worse. Try avoiding butter, margarine, cream sauces and fried foods.
Limit fiber, if it's a problem food: If you have inflammatory bowel disease, high-fiber foods, such as fresh fruits and vegetables and whole grains, may make your symptoms worse. If raw fruits and vegetables bother you, try steaming, baking or stewing them. In general, you may have more problems with foods in the cabbage family, such as broccoli and cauliflower, and nuts, seeds, corn and popcorn. You may be told to limit fiber or go on a low residue diet if you have a narrowing of your bowel (stricture).
Avoid other problem foods: Spicy foods, alcohol, and caffeine may make your signs and symptoms worse.
Eat small meals: You may find you feel better eating five or six small meals a day rather than two or three larger ones.
Drink plenty of liquids: Try to drink plenty of fluids daily. Water is best. Alcohol and beverages that contain caffeine stimulate your intestines and can make diarrhoea worse, while carbonated drinks frequently produce gas.
Multivitamins: Because Crohn's disease can interfere with your ability to absorb nutrients and because your diet may be limited, multivitamin and mineral supplements are often helpful. Check with your doctor before taking any vitamins or supplements.
Stop Smoking: Smoking increases your risk of developing Crohn's disease, and once you have it, smoking can make it worse. People with Crohn's disease who smoke are more likely to have relapses and need medications and repeat surgeries. Quitting smoking can improve the overall health of your digestive tract, as well as provide many other health benefits.
Exercise: Even mild exercise can help reduce stress, relieve depression and normalise bowel function. although stress doesn't cause Crohn's disease, it can make your signs and symptoms worse and may trigger flare-ups.
Biofeedback: This stress-reduction technique may help you reduce muscle tension and slow your heart rate with the help of a feedback machine. The goal is to help you enter a relaxed state so that you can cope more easily with stress. Regular relaxation and breathing exercises. One way to cope with stress is to regularly relax and use techniques such as deep, slow breathing to calm down. You can take classes in yoga and meditation or use books, CDs or DVDs at home.
Probiotics: There is some evidence to suggest that some Bifidobacterium preparations may help people with Crohn's disease to maintain remission, but some studies have found no benefits for treating Crohn's disease with probiotics. Further research is necessary to determine their effectiveness.
Fish oil: Studies done on fish oil for the treatment of Crohn's haven't shown benefit.
Prebiotics: Unlike probiotics — which are beneficial live bacteria that you consume — prebiotics are natural compounds found in plants, such as artichokes, that help fuel beneficial intestinal bacteria. Studies have not shown positive results of prebiotics for people with Crohn's disease.