Editing Ulcerative colitis (section)

== '''Pathophysiology''' ==

* Almost invariably involves the rectum, beginning at the dentate line
* Tends to involve more proximal parts of the colon in a continuous fashion
** Ulcerative proctitis - disease confined to the rectum
** Ulcerative proctosigmoiditis - disease limited to the rectum and sigmoid colon
** Left-sided colitis - disease that extends as far proximally as the splenic flexure
** Extensive colitis - disease extending proximal to the splenic flexure
* Natural history
** Typically, intermittent exacerbations alternating with long periods of complete symptomatic remission
** Those who present with just proctitis have a more benign long-term course
** 15% proceed to surgery