Ulcerative colitis is a form of inflammatory bowel disease that only affects the colon. It causes inflammation of the superficial layers of the colon to a varying extent resulting in “colitis”, or colon inflammation. Ulcerative colitis may only affect the rectum (proctitis) or the whole colon (total or pancolitis. Diarrhoea, with blood and mucus in the stool, and abdominal cramps are the most common symptoms of ulcerative colitis.