Inflammatory bowel disease (IBD) describes a group of conditions, the two main forms of which are Crohn's disease and ulcerative colitis. IBD also includes indeterminate colitis. Crohn's disease and ulcerative colitis are diseases that inflame the lining of the GI (gastrointestinal) tract and disrupt your body's ability to digest food, absorb nutrition, and eliminate waste in a healthy manner. These are lifelong disease and people can experience acute periods of active symptoms (active disease or flare), and other times when their symptoms are absent (remission).