Background
The term colitis refers to inflammation of the colon. It may be associated with enteritis (inflammation of the small intestine), proctitis (inflammation of the rectum), or both. Inflammatory bowel disease (IBD) is a generic term used to describe 3 idiopathic disorders that are associated with gastrointestinal (GI) inflammation:
Indeterminate colitis
IBD affects approximately 1.5 million Americans and worldwide, the incidence seems to be increasing. In 2012, a systematic review of all population-based studies describing the incidence and/or prevalence of IBD was performed. The review demonstrated that the incidence of IBD (both CD and UC) is increasing in many regions of the world. However, the incidence and prevalence of IBD remained highest in industrialized nations. Less data were available from developing countries, but the evidence suggests that IBD is emerging as a global disease.
In addition, numerous different conditions can cause colitis, each of which has its own pathophysiology. These include the following:
Necrotizing enterocolitis (NEC)
Allergic colitis
Pseudomembranous colitis
Infectious colitis (bacterial, parasitic, or viral)
Ischemic colitis
Colitis secondary to immune deficiency disorders