Ulcerative colitis

Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the top layers of the lining of the large intestine, affecting 1 to 1.5 million Americans each year. The inflammation usually occurs in the rectum and lower part of the colon, but it may affect the entire organ. Ulcerative colitis - which may also be called colitis, ileitis, or proctitis - rarely affects the small intestine.

The inflammation caused by ulcerative colitis makes the colon empty frequently, causing diarrhea. Ulcers form in places where the inflammation has killed colon lining cells; the ulcers bleed and produce pus and mucus.

Ulcerative colitis is an inflammatory bowel disease (IBD), the general name for diseases that cause inflammation in the intestines. Ulcerative colitis can be difficult to diagnose because its symptoms are similar to other intestinal disorders such as irritable bowel syndrome and to another type of IBD called Crohn's disease.

Men and women are affected equally by ulcerative colitis. It most commonly begins during adolescence and early adulthood, but it also can begin during childhood and later in life.

What causes ulcerative colitis?

There are many theories about what causes ulcerative colitis, but none have been proven. The most popular theory is that the body's immune system reacts to a virus or a bacterium by causing ongoing inflammation in the intestinal wall. The immune system is composed of immune cells and the proteins that these cells produce. These cells and proteins serve to defend the body against harmful bacteria, viruses, fungi, and other foreign invaders. Activation of the immune system causes inflammation within the tissues where the activation occurs.

Normally, the immune system is activated only when the body is exposed to harmful invaders. In patients with ulcerative colitis, however, the immune system is abnormally and chronically activated in the absence of any known invader. The continued abnormal activation of the immune systems causes chronic inflammation and ulceration. The susceptibility to abnormal activation of the immune system is genetically inherited.

What are the symptoms of ulcerative colitis?

The most common symptoms of ulcerative colitis are abdominal pain and bloody diarrhea, fever and nausea. Patients also may experience fatigue, weight loss, loss of appetite, rectal bleeding and loss of body fluids and nutrients. The severity of the symptoms often depends on where the ulcers are located, and whether the entire colon is affected.

Ulcerative colitis may also cause problems such as arthritis, inflammation of the eye, liver disease (fatty liver, hepatitis, cirrhosis, and primary sclerosing cholangitis), osteoporosis, skin rashes, anemia and kidney stones.

Both medications and surgery have been used to treat ulcerative colitis. Surgery is reserved for those with severe inflammation and life-threatening complications.