|Colitis refers to the acute or chronic inflammation of the membrane lining of the colon (large intestine or bowel) and can have many different causes. It is also the commonly used short name for ulcerative colitis, a condition which causes inflammation and ulcers in the top layers of the lining of the large intestine.
When inflammation occurs, the colon empties itself, frequently resulting in diarrhea. In areas where the inflammation has killed the colon lining cells, ulcers may develop which can then produce pus and mucus, or may also bleed.
People with inflammatory bowel disease also experience eye problems, joint problems, neck or lower back pain, as well as skin changes.