Description: The Abbott Laboratories drug Humira (adalimumab) has been approved for adults with moderate-to-severe Crohn's disease, a chronic inflammatory disease of the bowel, the U.S. Food and Drug Administration said Tuesday.

Crohn's affects about 500,000 people in the United States. Its varied symptoms may include persistent diarrhea, abdominal cramps, pain, fever, and fatigue. It may also cause unusual connections between the intestines and skin called fistulas. Most people with the disease are diagnosed between ages 15 and 35.

Humira works to reduce levels of human tumor necrosis factor (TNF) alpha, a chemical that plays a role in abnormal responses from the body's immune system, the FDA said.

Humira was initially approved to treat psoriatic arthritis in October 2005. It's also been sanctioned for moderate-to-severe rheumatoid arthritis, and an inflammatory disease of the spine called ankylosing spondylitis.

The drug's labeling includes a so-ca