IBS is a disorder affecting between 25 to 45 million people in the US who know all too well the disabling symptoms it can cause disrupting their lives. Irritable bowel syndrome (IBS) is an intestinal disorder causing pain in the belly, gas, bloating, cramping, diarrhea, and constipation.  Up to 1 in 5 Americans have chronic IBS with symptoms lasting for years or a lifetime.