Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the lining of the rectum and colon. Ulcers form where inflammation has killed the cells that usually line the colon, then bleed and produce pus. Inflammation in the colon also causes the colon to empty frequently, causing diarrhea.

When the inflammation occurs in the rectum and lower part of the colon it is called ulcerative proctitis. If the entire colon is affected it is called pancolitis. If only the left side of the colon is affected it is called limited or distal colitis.

Ulcerative colitis is an inflammatory bowel disease (IBD), the general name for diseases that cause inflammation in the small intestine and colon. It can be difficult to diagnose because its symptoms are similar to other intestinal disorders and to another type of IBD called Crohn's disease. Crohn's disease differs because it causes inflammation deeper within the intestinal wall and can occur in other parts of the digestive system including the small intestine, mouth, esophagus, and stomach.

Ulcerative colitis can occur in people of any age, but it usually starts between the ages of 15 and 30, and less frequently between 50 and 70 years of age. It affects men and women equally and appears to run in families, with reports of up to 20 percent of people with ulcerative colitis having a family member or relative with ulcerative colitis or Crohn's disease. A higher incidence of ulcerative colitis is seen in Whites and people of Jewish descent.

The most common symptoms of ulcerative colitis are abdominal pain and bloody diarrhea. Patients also may experience:

anemia
fatigue
weight loss
loss of appetite
rectal bleeding
loss of body fluids and nutrients
skin lesions
joint pain
growth failure (specifically in children)

About half of the people diagnosed with ulcerative colitis have mild symptoms. Others suffer frequent fevers, bloody diarrhea, nausea, and severe abdominal cramps. Ulcerative colitis may also cause problems such as arthritis, inflammation of the eye, liver disease, and osteoporosis. It is not known why these problems occur outside the colon. Scientists think these complications may be the result of inflammation triggered by the immune system. Some of these problems go away when the colitis is treated.

Many theories exist about what causes ulcerative colitis. People with ulcerative colitis have abnormalities of the immune system, but doctors do not know whether these abnormalities are a cause or a result of the disease. The body's immune system is believed to react abnormally to the bacteria in the digestive tract.

Ulcerative colitis is not caused by emotional distress or sensitivity to certain foods or food products, but these factors may trigger symptoms in some people. The stress of living with ulcerative colitis may also contribute to a worsening of symptoms.

Ulcerative colitis, an inflammatory disease of the large intestine, is at times difficult to diagnose right away due to its manifestations, which can mimic the symptoms of other diseases like Crohn's disease or irritable bowel syndrome.

The difference between the diseases is often only seen upon visualization of the colon, which will show deeper affected areas in diseases like Crohn's disease. Crohn's disease can also affect other parts of the GI tract like the mouth, esophagus, stomach and small intestine, while ulcerative colitis is only seen in the large intestine and the rectum. Colon cancer may also manifest symptoms similar to those found in ulcerative colitis, but the difference in this case is the presence of malignant cells in colon CA.

The most common symptoms of ulcerative colitis is a frequent urge to defecate and bloody diarrhea. The urge to defecate may come as often as 10 to 20 times a day and may cause the patient to wake up several times in the night.

The patient will also complain of abdominal pain, anemia, fatigue, weight loss, rectal bleeding and pain, malnutrition due to the lost nutrients, skin lesions, joint pain, and in children, stunted growth. Weight loss, malnutrition, and stunted growth in children may be the effects of frequent diarrhea, which can lead to severe nutrient loss. Frequent bleeding due to the presence of ulcers is the main cause of anemia. In severe cases, eye and liver problems may develop.

Arthritis, osteoporosis, and joint pain are also associated with ulcerative colitis, although the exact cause for this is not yet known. Scientists speculate that these may be a reaction to the inflammation's effect on the body's immune system.