Ulcerative colitis and
Crohn's disease are the most common forms of
inflammatory bowel disease (IBD). Some people have a nonspecific form of IBD
that is like ulcerative colitis but doesn't have all its features. This may be
a different type of ulcerative colitis.
For up to 10% of people who have symptoms, neither Crohn's disease
nor ulcerative colitis can be diagnosed.1 These people
have a form of IBD called indeterminate colitis, which doctors believe is a
combination of Crohn's disease and ulcerative colitis.