Risk factors

• Age. Most people who develop IBD are diagnosed before they're 30 years old. But some people don't develop the disease until their 50s or 60s.
• Race or ethnicity. Although whites have the highest risk of the disease, it can occur in any race.
• Family history. You're at higher risk if you have a close relative — such as a parent, sibling or child — with the disease.

• Cigarette smoking. Cigarette smoking is the most important controllable risk factor for developing Crohn's disease.

  Smoking may help prevent ulcerative colitis. However, its harm to overall health outweighs any benefit, and quitting smoking can improve the general health of your digestive tract, as well as provide many other health benefits.

• Nonsteroidal anti-inflammatory medications. These include ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve), diclofenac sodium and others. These medications may increase the risk of developing IBD or worsen the disease in people who have IBD.