Q: My friend has a 17-year-old son who was diagnosed with Crohn's disease three years ago. I would like to know more about it? What causes it? Does stress play a factor? Can diet alleviate symptoms?
-- K.M., Trumbull, Conn.
A: Crohn's disease is thought to be an autoimmune disease in which the immune system attacks the body. But recent evidence strongly suggests it is associated with infection from the MAP virus, which may be the trigger for the immune system.
It's one of two types of chronic, idiopathic inflammatory bowel diseases. The other is called ulcerative colitis. The term idiopathic means that the specific cause is unknown.
In those with Crohn's disease, patches of inflammation and ulcers appear on and within the lining of the gastrointestinal tract. These patches can be anywhere from the mouth to the anus. In one-third of Crohn's cases, only the small intestine is involved; in more than half the cases, only the small and large intestines are affected. In the rest, inflammation and ulcers appear in other parts of the GI tract.
Cramping abdominal pain and diarrhea are the usual symptoms. But some people also have low-grade fever, a general feeling of illness (malaise), weight loss (especially muscle mass) and loss of energy.
Complications can include bowel abscesses, obstructions and fistulas (openings in the intestinal wall connecting to other abdominal structures).
Because the symptoms of Crohn's disease overlap with other gastrointestinal problems, three out of four people with Crohn's are not given the correct diagnosis on their first doctor visit. Even more unfortunate is that one-third of people will have to visit four different doctors before the diagnosis is made.
Diet is not the mainstay of treatment, but dietary changes can alleviate some symptoms. The important point is for each person to identify any foods that may be problem, such as those containing caffeine, and eliminate them from the diet.
Stress may be a factor in worsening any disease of the intestines, but there is no evidence that stress is a factor in causing Crohn's disease.
For many years, steroids and aminosalicylic acids were the only drugs used to treat Crohn's. Although steroids work well initially, their effect tends to wear off and side effects can be severe. A new steroid called budesonide has fewer side effects, and many experts now recommend it to be used as the first course of treatment for those whom the disease affects in the small intestine.
Although antibiotics have been used for years, there is little evidence that these work well. More recent research has shown that methotrexate, thalidomide, and two immune modulators, infliximab and natalizumab, are helpful.
More than half the people with Crohn's disease will benefit from surgery to remove part of the intestine. Surgery that removes large portions of the intestines will change the ability to handle certain foods (depending on what part of the intestine was removed). So if surgery is done, it's important to discuss and follow recommended dietary changes.
In more severe cases, the removal of the entire small intestine may be recommended. But about half the time this will require a permanent hole (stoma) in the wall of the abdomen for discharge of intestinal contents.