Inflammatory bowel disease (which is not the same thing as irritable bowel syndrome, or IBS) refers to two chronic diseases that cause inflammation of the intestines: ulcerative colitis and Crohn's disease. Although the diseases have some features in common, there are some important differences.
The most common symptoms of both ulcerative colitis and Crohn's disease are diarrhea and abdominal pain. Diarrhea can range from mild to severe (as many as 20 or more trips to the bathroom a day). If the diarrhea is extreme, it can lead to dehydration, rapid heartbeat, and a drop in blood pressure. And continued loss of small amounts of blood in the stool can lead to anemia.
At times, those with inflammatory bowel disease may also have constipation. With Crohn's disease, this can happen as a result of a partial obstruction (called stricture) in the intestines. In ulcerative colitis, constipation may be a symptom of inflammation of the rectum.
The exact causes are unknown. The disease may be caused by a germ or by an immune system problem. You don't have to worry about your family members catching the disease from you, because it isn't contagious. However, inflammatory bowel disease does seem to be hereditary.