Ulcerative colitis is a chronic disease that results in inflammation of the colon's innermost layer.

Colitis refers to an inflammation of the colon. Colitis may be acute and self-limited or chronic, i.e. persistent, and broadly fits into the category of digestive diseases. The signs and symptoms of colitis are quite variable and dependent on the cause of the given colitis and factors that modify its course and severity. Symptoms of colitis may include: mild to severe abdominal pain and tenderness (depending on the stage of the disease), recurring bloody diarrhea with/without pus in the stools, fecal incontinence, flatulence, fatigue, loss of appetite and unexplained weight loss.

Ulcerative colitis is a disease that causes inflammation and sores (ulcers) in the lining of the large intestine. It usually affects the lower section (sigmoid colon) and the rectum. But it can affect the entire colon. In general, the more of the colon that's affected, the worse the symptoms will be.

The disease can affect people of any age. But most people who have it are diagnosed before the age of 30.

Experts aren't sure what causes it. They think it might be caused by the immune system overreacting to normal bacteria in the digestive tract. Or other kinds of bacteria and viruses may cause it.

You are more likely to get ulcerative colitis if other people in your family have it.