A disorder with chronic or recurrent colonic symptoms without a clearcut etiology. This condition is characterized by chronic or recurrent ABDOMINAL PAIN, bloating, MUCUS in FECES, and an erratic disturbance of DEFECATION. A syndrome that is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. Irritable bowel syndrome (IBS) is a chronic functional condition of the lower gastrointestinal (GI) tract characterized by abdominal pain or discomfort and disordered bowel habit (diarrhea, constipation, or fluctuation between the two).