Ulcerative colitis should be considered in any patient with chronic diarrhea or rectal bleeding. Diagnosis depends on a combination of findings from physical, laboratory, endoscopic, and histopathologic examinations, together with the exclusion of other causes and continued observation over time. The mainstays of treatment are sulfasalazine for mild to moderate disease and corticosteroids for moderate to severe disease. Side effects of sulfasalazine, due to the sulfa moiety of the drug, limit its use in some patients. Newer, sulfa-free 5-ASA agents, although expensive, are appropriate for patients who cannot tolerate sulfasalazine. Refractory ulcerative colitis is best treated surgically. Most patients require maintenance therapy with sulfasalazine or a sulfa-free 5-ASA preparation. Cancer risk is increased in patients with long-standing ulcerative colitis.