For the half-million Americans with Crohn’s disease, finding relief from abdominal pain and digestive problems is an ongoing challenge.  Conventional therapies like steroids are often effective, but some patients find that they don’t do enough to calm their troubling symptoms.

Fortunately, in the past few years a wider range of treatments has become available for people with Crohn’s disease.  Other experimental drugs are showing promise in clinical trials.  But even the newest treatments have plusses and minuses.  That’s why NIH researchers are continuing to investigate Crohn’s disease.  They hope to discover who’s at risk so they can block the disease before it appears.  And they’re exploring a variety of new treatments.

Crohn’s disease arises from inflammation, or swelling, of the digestive tract, usually in the small intestines.  Its symptoms include abdominal cramps, diarrhea, weight loss, malnourishment and rectal bleeding.  In some cases, the intestine can become blocked or develop open sores, or ulcers. The ulcers sometimes tunnel through to other tissues.

Most people are diagnosed with Crohn’s disease in their 20s, although it can affect people of any age.  The symptoms often come and go throughout a person’s life.  In many cases, they get worse over time. 

Scientists are not yet certain what causes Crohn’s disease.  Many believe it’s set off when the immune system misidentifies harmless bacteria, foods and other substances in the digestive tract as dangerous invaders.  White blood cells are sent to attack these “invaders” and may build up in the lining of the intestines.  The buildup of cells can cause long-term inflammation and ulcers. 

The current treatments available for Crohn’s disease each come with their own risks and benefits.  NIH-funded research helped lay the groundwork for some of the newest therapies.  One new type of drug blocks an inflammation-causing molecule called tumor necrosis factor (TNF).  So far, the U.S.  Food and Drug Administration (FDA) has approved 2 anti-TNF drugs—Remicade and Humira—for treating Crohn’s disease.  About half of Crohn’s patients find anti-TNF drugs helpful.

In January 2008, the FDA approved another new drug, called Tysabri, that blocks white blood cells from moving to inflamed tissues.  Tysabri seems to help many patients who don’t respond to anti-TNF drugs.  But the new drug can have severe and even deadly side effects, so patients have to be carefully monitored. 

Another promising approach was developed more than a decade ago by NIH researchers.  This experimental treatment blocks immune molecules called interleukins.  In 2004, a clinical trial showed that up to 3 out of every 4 patients with Crohn’s disease responded to an interleukin-blocking drug.  Up to half had long-term freedom from symptoms.  The drugs, which are not available to the public, are now being tested in large clinical trials.