Ulcerative colitis is a disease in which inflammation and ulcers appear on the lining of the large intestine and the rectum, according to Mayo Clinic. Medical professionals are not sure what causes ulcerative colitis, but some believe that it results from a malfunction of the patient's immune system.
There are several subtypes of ulcerative colitis, according to the Crohn's & Colitis Foundation of America. In ulcerative proctitis, the inflammation is restricted to the rectum, which makes it a milder form of the disease. In proctosigmoiditis, the disease affects both the rectum and the sigmoid colon. Left-sided colitis is found in the rectum and travels upward to the bend in the colon near the spleen. Pan-ulcerative colitis involves the entire colon and can have serious complications.
The severity of the symptoms of ulcerative colitis depends on how much of the colon is involved, according to the Crohn's & Colitis Foundation of America. Patients may experience loose bowel movements, an urge to evacuate the bowels and persistent, bloody diarrhea with abdominal cramps. They may also experience fatigued and a loss of appetite. However, the symptoms come and go, and some patients can spend years in remission.
Men and women are equally at risk for ulcerative colitis, according to the Crohn's & Colitis Foundation of America. Although it develop in children, most patients are first diagnosed in their 30s.