IBD is a disease with an unknown cause. Some agent or a combination of agents -- bacteria, viruses, antigens -- triggers the body's immune system to produce an inflammatory reaction in the intestinal tract. Recent studies show some combination of hereditary, genetic, and/or environmental factors may cause the development of IBD. It could also be that the body's own tissue causes an autoimmune response. Whatever causes it, the reaction continues without control and damages the intestinal wall, leading to diarrhea and abdominal pain.

There is strong evidence to suggest a genetic basis for IBD, including:

• Family history: As many as 20% of people with IBD have a family history.
• Race and ethnicity: IBD is more common in caucasians.

As with other chronic diseases, a person with IBD will generally go through periods in which the disease flares up and causes symptoms, followed by periods in which symptoms decrease or disappear and good health returns. Symptoms range from mild to severe and generally depend upon what part of the intestinal tract is involved. They include:

• Abdominal cramps and pain
• Diarrhea that may be bloody
• Severe urgency to have a bowel movement
• Fever
• Weight loss
• Loss of appetite
• Iron deficiency anemia due to blood loss

IBD can lead to several serious complications in the intestines, including:

• Profuse intestinal bleeding from the ulcers
• Perforation, or rupture of the bowel
• Narrowing - called a stricture -- and obstruction of the bowel; found in Crohn's
• Fistula (abnormal passages) and perianal disease, disease in the tissue around the anus; these conditions are more common in Crohn’s than in ulcerative colitis.
• Toxic megacolon, which is an extreme dilation of the colon that is life-threatening; this is associated more with ulcerative colitis than Crohn's.
• Malnutrition

IBD increases the risk of colon cancer. IBD can also affect other organs; for example, someone with IBD may have arthritis, skin conditions, inflammation of the eye, liver and kidney disorders, or bone loss. Of all the complications outside the intestines, arthritis is the most common. Joint, eye, and skin complications often occur together.

We make the diagnosis of inflammatory bowel disease based on your symptoms and various exams and tests:

• Stool exam. You'll be asked for a stool sample that will be sent to a laboratory to rule out the possibility of bacterial, viral, or parasitic causes of diarrhea. In addition, the stool will be examined for traces of blood that cannot be seen with the naked eye.
• Blood tests.
• Complete blood count--An increase in the white blood cell count suggests the presence of inflammation. And if you have severe bleeding, the red blood cell count and hemoglobin level may decrease.
• Electrolytes (sodium, potassium), protein, and markers of inflammation, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), may be drawn to look at disease severity.
• Perinuclear antineutrophil cytoplasmic antibody (pANCA) levels may be up in ulcerative colitis. In addition, specific tests for sexually transmitted diseases may be done.
• Barium X-ray. Although seldom used, it can check the upper gastrointestinal (GI) tract -- the esophagus, stomach, and small intestine -- for abnormalities caused by Crohn's disease. You swallow a chalky white solution that coats the intestinal tract so it will be visible on X-rays. If a barium study is used to check the lower GI tract, you will be given an enema containing barium and asked to hold it in while X-rays are taken of the rectum and colon. Abnormalities caused by either Crohn's or ulcerative colitis may show up in these X-rays.
• Other radiologic tests. Computed tomography (CT scan), magnetic resonance imaging (MRI), and ultrasound have also been used in the diagnosis of Crohn’s disease and ulcerative colitis.
• Sigmoidoscopy. In this procedure, a doctor uses a sigmoidoscope, a narrow, flexible tube with a camera and light, to visually examine the last one-third of your large intestine, which includes the rectum and the sigmoid colon. The sigmoidoscope is inserted through the anus and the intestinal wall is visually examined for ulcers, inflammation, and bleeding. The doctor may also take samples -- biopsies -- of the intestinal lining with an instrument inserted through the tube. These will then be examined in a laboratory under a microscope.
• Colonoscopy. A colonoscopy is similar to a sigmoidoscopy, except that the doctor will use a colonoscope, a longer flexible tube, to examine the entire colon. This procedure is performed under anesthesia and gives a complete look at the extent of disease in the colon.
• Upper endoscopy. If you have upper GI symptoms such as nausea and vomiting, a doctor will use an endoscope, a narrow, flexible tube with a camera and light, that will be inserted through the mouth -- to examine your esophagus, stomach, and duodenum, which is the first part of your small intestine.
• Capsule endoscopy. This test may be helpful to diagnose disease in the small intestine, such as in Crohn’s disease. You swallow a small capsule that has a camera in it. Pictures are taken of the esophagus, stomach and small bowel and then sent to a receiver you wear on a belt. At the end of the procedure, the pictures are downloaded from the receiver onto a computer. The camera is passed through your body into the toilet.