Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal pain, cramps, bloating, and altered bowel habits that may include diarrhea and/or constipation. As a functional disorder, it is not linked to tissue damage and is diagnosed by criteria related to key symptoms. Importantly, IBS should not be confused with inflammatory bowel disease (IBD), a broad term describing conditions characterized by chronic inflammation of the gastrointestinal tract.