A bowel disease that is characterized by inflammation with ulcer formation in the lining of colon (large intestine). Its cause is unknown. The end of the colon (the rectum) is generally involved. When limited to the rectum, the disease is called ulcerative proctitis. The inflammation may extend to varying degrees into the upper parts of the colon. When the entire colon is involved, it is referred to as pancolitis or universal colitis. Symptoms include intermittent rectal bleeding, crampy abdominal pain, and diarrhea. Many patients experience long remissions, even without medication. Ulcerative colitis may mysteriously If inflammation goes unchecked, it can damage cartilage, the elastic tissue that covers the ends of bones in a joint, as well as the bones themselves. Over time, there is loss of cartilage, and the joint spacing between bones can become smaller. Joints can become loose, unstable, painful and lose their mobility. Joint deformity also can occur. Joint damage cannot be reversed, and because it can occur early, doctors recommend early diagnosis and aggressive treatment to control RA. ( source : Arthritis foundation).