Crohn's Disease

What is Crohn's Disease?

Crohn's disease is a disease of the digestive system where the intestines, and sometimes the whole digestive system from mouth to anus, becomes stricken with inflammation, causing a variety of symptoms. This disease belongs to the group of inflammatory bowel diseases, and is also known as regional enteritis and granulomatous ileocolitis. The disease is named after the gastroenterologist Burrill Bernard Crohn of the United States who first described the condition in 1932.

Crohn's disease commonly affects the part of the intestine called the ileum and often appears first in this region. There is a swelling that extends down to the initial lining of the organ and causes abdominal pain and irritation to the intestines. In turn, this will accelerate food passage and rapid emptying results in diarrhea. The inflammation spreads along the length of the intestinal tract: up to the stomach, esophagus and mouth; and down to the rectum and anus. Inflammation also penetrates deep into the three layers of the digestive organs. The name "regional enteritis" is derived from this characteristic.

The inflammation is so intense that ulcers may form at the site and can spread to cover a large area. The inflammation tends to form at different places and the ulcers may be separated by sections of relatively normal tissue. Crohn's disease severely damages the lining of the gastrointestinal tract that prevents absorption of essential nutrients, vitamins, water and fats from the food. This causes problems in terms of the immune resistance and may result in malnutrition and dehydration, along with different vitamin deficiencies. Another consequence of inflammation is the swelling of the intestinal lining. This may eventually cause constriction and stop passage of food. The constriction may subside if the inflammation is resolved. However, in some cases the condition may become permanent. The obstruction in conjunction with diarrhea, leads to a dangerous buildup of intra-intestinal pressure. This may cause a rupture of the intestinal wall and invasion of the abdominal cavity by intestinal contents leading to a life-threatening infection.

Crohn's disease also affects areas other than the gastrointestinal tract and can induce symptoms in the eyes, nervous system, joints and muscles, bones, skin lesions and blood clotting problems.

The disease is a part of a group of intestinal disorders called inflammatory bowel diseases. The group is composed of ulcerative colitis, irritable bowel syndrome and Crohn's disease. Crohn's disease is often confused with these conditions, but can be distinguished by the presence of overall digestive tract inflammation with symptoms outside of the digestive system.

The direct cause of inflammation is still unclear, but it is usually thought of as a consequence of autoimmunity, a condition in which the immune system attacks normal intestinal tissues. The disease seems to run in families, and therefore is hypothesized that it has a genetic component. On the other hand, Crohn's disease seems to be triggered by environmental factors and is more frequent in the industrialized world. The incidence is higher in the United States, with 7 cases per 100,000 people where it is more frequent in urban areas. It affects both males and females and is twice more frequent in smokers. It is more prevalent in whites, and particularly common among Jewish people relative to other ethnic groups. It can occur at any age and the disease may initially present itself during the teenage years or as late as sixty years of age.

Currently there is no medical and/or surgical cure for patients with Crohn's disease. Its symptoms may disappear for some time, but the disease might relapse. The goals of current management for Crohn's disease are to induce remission and prevent relapse.

What Causes Crohn's Disease?

The exact cause of Crohn's disease is unknown. According to a medical theory, it is caused by an abnormal autoimmune response, that instead of targeting outside bacteria, it attacks the intestines and causes inflammation which is part of the immune response.

Due to its incidence along hereditary lines, the disease is thought to have a genetic component however the genetic factor has not been conclusively identified. In recent studies, NOD2 has been identified as a gene potentially involved in the development of Crohn's disease.

Environment may also play a role in the development of Crohn's disease since it most frequently affects individuals who smoke and/or live in polluted environment. According to the immunological theory, these environmental factors may trigger a faulty gene which, in turn, leads the immune system to attack the intestines as a response.

Certain fecal bacteria are also thought to be involved in the pathogenesis of Crohn's disease. Mycobacterium avium, a tuberculosis agent, and E. coli, part of the normal flora of the intestine but with pathogenic potential, can potentially cause infection and inflammation that might be associated with this disease. Other suspected agents include bacteria, such as Yersinia and Listeria species, and protozoans, such as Blastocystis.

Symptoms of Crohn's Disease

The symptom of Crohn's disease is divided into three classes: intestinal, extra-intestinal and systemic.

Intestinal symptoms:

• Abdominal pain, often in the lower right side
• Diarrhea, often more than 6 bowel movements a day, with or without blood
• Flatulence and bloating
• Increase in stomach sounds, which can be a sign of obstruction as the intestines make more effort to move food through narrow passages
• Pain, itchiness and eventual bleeding in the rectum
• Non-healing apthous cankers in the mouth
• Difficulty in swallowing
• Vomiting

Extra-intestinal symptoms:

• Inflammation of parts of the eyes
• Photophobia
• Inflammation of the joints (arthritis) and muscles
• Back problems
• Skin eruptions on the shin areas
• Appearance of painful, ulcerating wound with nodules
• Painful swelling in the calf (deep venous thrombosis)
• Sudden difficulty of breathing (pulmonary embolism), an emergency and fatal if not addressed quickly
• Anemia, due to immune system attacking red blood cells
• Clubbing of the nails (related to anemia states)
• Osteoporosis, and increased risk of bone fractures
• Seizures, sudden stroke, headache and depression

Systemic symptoms that often appear in severe cases:

• Failure to strive in children, especially apparent if the child is undergoing puberty
• Fever
• Weight loss

Diagnosis of Crohn's Disease

The diagnosis often requires a complex set of exams, as Crohn's disease patients may have a large variety of symptoms that share a number of similarities with irritable bowel disease and ulcerative colitis. Even after completing the whole series of tests, there may still be uncertainties. The diagnosis itself is challenging to the doctor, because it is difficult to adequately support Crohn's disease as the condition responsible for the symptoms.

Blood tests are initially performed to check for anemia, presence and degree of inflammation and the existence of antibodies that target the body's own tissues.

Endoscopy is performed to visualize the colon and ileum (colonoscopy) and the esophagus (esophageal endoscopy). During endoscopy, a sample of tissue for biopsy can also be obtained after attaching small surgical instruments to the endoscope (a thin tube with a light and small camera).

Abdominal X-ray with barium swallow or enema is performed to visualize the intestinal structure. The barium coats the intestinal wall, enabling visualization of this structure in the x-ray film. This procedure is useful for the identification of anatomical abnormalities and to evaluate the magnitude of intestinal strictures.

Computerized tomography (CT) and magnetic resonance imaging (MRI) scans are used to visualize the intestines as well as the whole body for extra-intestinal symptoms such as abscess and bone problems.

Treatment of Crohn's Disease

There is no existing cure for Crohn's disease. Currently, the goals of treatment are symptom management, enhancement of remission and prevention of recurrence. The disease is managed through the use of drugs, lifestyle modifications and surgery.

Medications given are normally to fight infectious bacteria and manage infection and inflammation:

Antibiotics are chosen according to the perceived and identified microbes.

Anti-inflammatory drugs are critical to address the most prominent symptom of Crohn's disease: inflammation. Corticosteroids such as prednisone are potent anti-inflammatories, but cannot be used during a long period of time because they have serious side effects. Aminosalicylates are used to decrease inflammation, but have only limited efficacy and must be used along with immunosuppressants like azathioprine, mercaptopurine, and methotrexate. Low dose of opium antagonist naltrexone is used to enhance and accelerate the disappearance of symptoms.

Biological medications such as infliximab and adalimumab contain live cells that target the white blood cells. White blood cells are responsible for the attack on the body's own tissues (auto-immune response).

Surgery is warranted when there is a blockage of the intestine due to strictures, fistulas and abscesses. The section of intestine with the blockage is normally removed. However, ulcers appear frequently at the site of the resection and scar tissue builds up, causing additional narrowing and eventually blockage. Because of these complications from surgery and due to potential relapse of the disease, a patient often requires surgery every five years to remove blocked intestines.

It is also possible to just remove the stricture without resecting a segment of the intestine. These approaches have less impact on the patient and have been shown to be more effective. However, due to the severe nature of some cases, is not always possible to use techniques not involving bowel resection.

Alternative Treatment

Keeping a healthy lifestyle by avoiding exposure to smoke and by implementing diet changes is a very important aspect of the treatment of Crohn's disease.

Patients are encouraged to eat more fruits, whole grains and leafy vegetables; to drink plenty of water; to exercise regularly; and to rest properly. Large meals are replaced with smaller and more frequent meals. Foods are identified that can disturb normal digestion and removed from the diet.

Prognosis of Crohn's Disease

Crohn's disease is incurable and will last for life. The course of the disease consists in periods of improvement followed by a sudden appearance of symptoms. A Crohn's disease patient can still have a normal life if the symptoms are controlled. Although the mortality rate is low, a person with Crohn's disease has a higher risk of cancer in the small intestines, colon, anus and rectum.

Preventing Crohn's Disease

It is difficult to prevent Crohn's disease without knowing its exact causes. Since some environmental factors are associated with the disease, avoiding these conditions may help in preventing the appearance or recurrence of this disease. Maintaining a healthy diet and lifestyle can help to prevent Crohn's disease and other conditions.

Living with Crohn's Disease

Having Crohn's disease can be debilitating, but normal life is possible as long as you keep track of your diet with a food diary and comply with your medication. However, a severe case with a lot of symptoms can be very distressing both to the patient and the caregiver or family. Reporting symptoms to the doctor is very important and they have ways to cope with emergency situations like a sudden difficulty of breathing, stroke, open fractures and intestinal perforation. Keeping a list of medications can help prevent overdose or under dose of the multiple medications. As many as half of the patients try complementary and alternative medicine. This is fine as long as it is told to the attending doctor, because some of it might interfere with the drugs or might do more harm to the patient.

In the event of a surgery, the patient must be made aware of the symptoms of short bowel syndrome as it can cause further diarrhea and dehydration. The arranged diet must be followed, as the patient may lose appetite because they feel better, but it may cause the patient to fall short on the required nutrients and vitamins.

Current Research of Crohn's Disease

Research at the University College of London showed positive response when a patient was given sildenafil citrate (Viagra) to increase blood flow into the intestines, questioning the treatment using immunosuppressive drugs.

The use of helminthic therapy, induction of parasites such as hookworms to the digestive tract of patients with Crohn's disease has shown promising results.

Cannabis-derived drugs with anti-inflammatory properties, such as marinol, are being investigated for their potential role in relieving the symptoms of the disease.