Ulcerative colitis.

Ulcerative colitis is an idiopathic, chronic inflammatory disorder of the colonic mucosa, which starts in the rectum and generally extends proximally in a continuous manner through part of, or the entire, colon; however, some patients with proctitis or left-sided colitis might have a caecal patch of inflammation. Bloody diarrhoea is the characteristic symptom of the disease. The clinical course is unpredictable, marked by alternating periods of exacerbation and remission. In this Seminar we discuss the epidemiology, pathophysiology, diagnostic approach, natural history, medical and surgical management, and main disease-related complications of ulcerative colitis, and briefly outline novel treatment options. Enhanced understanding of how the interaction between environmental factors, genetics, and the immune system results in mucosal inflammation has increased knowledge of disease pathophysiology. We provide practical therapeutic algorithms that are easily applicable in daily clinical practice, emphasising present controversies in treatment management and novel therapies.