Crohn’s – A chronic inflammatory disease, primarily involving the small and large intestine, but which can affect other parts of the digestive system as well. … The most common part of the small intestine to be affected by Crohn disease is the last portion, called the ileum.

Ulcerative Colitis – A bowel disease that is characterized by inflammation with ulcer formation in the lining of the colon (large intestine). Its cause is unknown. The end of the colon (the rectum) is generally involved.

Symptoms

Inflammatory bowel disease symptoms vary, depending on the severity of inflammation and where it occurs. Symptoms may range from mild to severe. You are likely to have periods of active illness followed by periods of remission.

Signs and symptoms that are common to both Crohn’s disease and ulcerative colitis include:

• Diarrhea
• Fever and fatigue
• Abdominal pain and cramping
• Blood in your stool
• Reduced appetite
• Unintended weight loss

Causes

The exact cause of inflammatory bowel disease remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but don’t cause IBD.

One possible cause is an immune system malfunction. When your immune system tries to fight off an invading virus or bacterium, an abnormal immune response causes the immune system to attack the cells in the digestive tract, too. Heredity also seems to play a role in that IBD is more common in people who have family members with the disease. However, most people with IBD don’t have this family history.

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. If you’re of Ashkenazi Jewish descent, your risk is even higher.
• 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. Although smoking may provide some protection against ulcerative colitis, the overall health benefits of not smoking make it important to try to quit.
• Nonsteroidal anti-inflammatory medications. These include ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve), diclofenac sodium (Voltaren) and others. These medications may increase the risk of developing IBD or worsen disease in people who have IBD.
• Where you live. If you live in an industrialized country, you’re more likely to develop IBD. Therefore, it may be that environmental factors, including a diet high in fat or refined foods, play a role. People living in northern climates also seem to be at greater risk.

Complications

Ulcerative colitis and Crohn’s disease have some complications in common and others that are specific to each condition. Complications found in both conditions may include:

• Colon cancer. Having IBD increases your risk of colon cancer. General colon cancer screening guidelines for people without IBD call for a colonoscopy every 10 years beginning at age 50. Ask your doctor whether you need to have this test done sooner and more frequently.
• Skin, eye and joint inflammation. Certain disorders, including arthritis, skin lesions and eye inflammation (uveitis), may occur during IBD flare-ups.
• Medication side effects. Certain medications for IBD are associated with a small risk of developing certain cancers. Corticosteroids can be associated with a risk of osteoporosis, high blood pressure and other conditions.
• Primary sclerosing cholangitis. In this condition, inflammation causes scars within the bile ducts, eventually making them narrow and gradually causing liver damage.
• Blood clots. IBD increases the risk of blood clots in veins and arteries.