Inflammatory bowel disease (IBD) is not a single disease. The term IBD is used mainly to describe two diseases:

Crohn’s disease
ulcerative colitis

Both Crohn’s disease and ulcerative colitis are chronic (long-term) diseases that involve inflammation of the gastrointestinal tract (gut). However, there are important differences between the two.

Read more: http://drbcshah.com/inflammatory-bowel-disease/