Ulcerative proctitis: Inflammation is confined to the area closest to the anus (rectum), and rectal bleeding may be the only sign of the disease.
Proctosigmoiditis: Inflammation involves the rectum and sigmoid colon — the 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 urgency to defecate.
Pancolitis: This type often affects the entire colon and causes bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue, and significant weight loss.
Causes:
The exact cause of ulcerative colitis remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but don't cause ulcerative colitis. One possible cause is an immune system malfunction. When your immune system tries to fight off an invading virus or bacterium, an abnormal immune response causes the immune system to attack the cells in the digestive tract, too.
Courtesy: Mayo Clinic
