Doctors often classify Ulcerative Colitis by its location. Ulcerative proctitis - inflammation is confined to the area closest to the anus (rectum), and rectal bleeding may be the only sign of the disease. This form of ulcerative colitis tends to be the mildest. Proctosigmoiditis - inflammation involves the rectum and sigmoid colon (lower end of the colon). Signs and symptoms include bloody diarrhea, abdominal cramps and pain, and an inability to move the bowels in spite of the urge to do so (tenesmus) Left-sided colitis - inflammation extends from the rectum up through the sigmoid and descending colon. Signs and symptoms include bloody diarrhea, abdominal cramping and pain on the left side, and unintended weight loss. Pancolitis - affects the entire colon and causes bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue, and significant weight loss. Acute severe ulcerative colitis - rare form of colitis affects the entire colon and causes severe pain, profuse diarrhea, bleeding, fever and inability to eat.