Inflammatory bowel disease (IBD) — not to be confused with irritable bowel syndrome (IBS) — is an autoimmune disease that can have very serious consequences. (IBS, on the other hand, is a functional bowel disorder. In other words, there are no significant physical conditions that contribute to the problem; hence it's a functional disease.) According to the latest statistics from the Centers for Disease Control and Prevention (CDC), IBD affects more than 3 million American adults, nearly triple previous estimates.1 There are two types of IBD: Crohn's disease Ulcerative colitis Both of these IBD conditions involve chronic inflammation in the gastrointestinal (GI) tract. Symptoms include abdominal cramps, fatigue and diarrhea. IBD also raises your risk of developing colorectal cancer, the third most common cancer in the U.S.