What is Crohn’s disease and how does it affect the body?
Crohn’s disease is an inflammatory disease, which can involve any gastrointestinal organ such as the esophagus, stomach, small intestine, colon, anus, liver and bile duct. The intestines are initially affected by superficial ulceration and inflammation, which may result in diarrhea, abdominal pain, fever or bleeding. In the intestine and anal canal, deeper ulceration leads to perforation and scar tissue. Perforation can lead to abscesses, fistulas (deep tracts leading to other areas of the body) and peritonitis. Scar tissue leads to strictures or narrowing of the intestine and obstruction. The most common area to be affected is the junction of the small and large intestine (known as the ileocecal area), followed by the large intestine alone, followed by the small intestine alone. The bile ducts can be scarred by inflammation (sclerosing cholangitis). Gallstones develop in 30% of people with Crohn’s disease. Mild liver disease or pericholangitis occurs occasionally. As part of the overall Crohn’s disease, 5% of people experience joint and low back pain, a variety of skin and eye diseases, fever and anemia.
What is the cause for Crohn’s disease?
Although no one knows what starts this disease, many aspects of the inflammatory process are known. There appears to be a genetic predisposition to the disease. Crohn’s disease may start after a gastrointestinal infection where certain inflammatory cells get stimulated and stay that way for uncertain reasons.
What is the long-term outlook for people with Crohn’s disease?
This disease becomes active and goes into remission without any predictability. After a person goes into a drug-induced remission, relapse occurs in 25-50% after 1 year and 40-65% after 2 years. When the disease has required surgical removal of the inflamed area, relapse in another part of the intestine (usually where it was reconnected) occurs in 30-60% within 5 years and 50-80% by 10 years. The re-operation rate is higher for ileocecal vs. ileal vs. colon surgery. One factor that has clearly been recognized in reactivation of Crohn’s disease is cigarette smoking. Smokers have double the relapse rate and double the number of surgeries as compared to non-smokers and ex-smokers. This may be related to the microcirculation and the vascular leakiness of the intestine.
What is the treatment for Crohn’s disease?
Usually the first treatment is one of the 6-ASA medications (Asacol, Rowasa, Pentasa, Dipentum, Colazal and Azulfidine). This class of medications decreases mucosal permeability, inhibits antibody production, inhibits chemotactic factor production and stimulates prostaglandin production. For moderate or severe disease, an anti-inflammatory steroid called prednisone is commonly prescribed. This drug is similar to a chemical that our own body makes but when used in high doses it has many short-term and long-term side effects. A third class of medications called immunosupressants or immunomodulating medications are useful in minimizing the dose or replacing the use of steroids. Examples include Purinethol (6-MP; mercaptopurine), Imuran (azathiaprine) and methotrexate. Each of these medications potentially has significant side effects that require careful monitoring by your doctor. A new form of treatment was approved by the Food and Drug Administation in 1999 for use in patients with moderately to severely active Crohn's disease and fistulas. Infliximab (trade name Remicaide) is a medication given intravenously as an infusion over several hours. It works relatively quickly, is well tolerated and the effect can last weeks to months, but sometimes repeat treatment is needed. Antibiotics such as Cipro and Flagyl can be helpful in the treatment of the inflammation and infection associated with Crohn’s disease. Finally, surgery is indicated for patients who have strictures with obstruction, perforation and when medical therapy has failed. When patients have short strictures at surgical connections, we have had success with balloon dilation and local steroid injection during endoscopy. Heparin and Plaquenil are other helpful treatments.
After surgical resection of part of the small intestine a bile acid binder such as Questran or Colestipal may be indicated to limit diarrhea. Anti-diarrhea and anti-spasmotics can be helpful medications. Other less well documented treatments that may have merit include the use of fish oil capsules, which are a source of Omega-3 (n-3) fatty acids. One problem with taking fish oil is to know which preparation is best. There was only one medical study that showed a clinically significant effect and this formulation is not available in America. Two other problems include a fishy breath and the expense of the tablet.
How should the diet be modified?
Certain modifications in diet are indicated. When there is a narrowed area in the intestine, raw fruits and vegetables should be avoided. When the intestinal disease is active these foods will also contribute to diarrhea. Caffeine may be a factor in contributing to diarrhea. We do not limit dairy products although a lactose enzyme supplement is indicated for those who are intolerant to the milk sugar. Limitation of highly refined sugars may be helpful. When tolerated, increasing the dietary fiber may be helpful. A balanced nutritious diet with vitamin supplementation is important. Vitamin B12 and vitamin D may need special prescriptions when clinically indicated. After surgical resection of part of the small intestine a low oxylate diet and increased fluid intake may be indicated to prevent kidney stones.