Irritable bowel syndrome (IBS) is characterized by chronic episodic abdominal pain or discomfort that is associated with relapsing and remitting constipation and/or diarrhea. The most recent diagnostic criteria proposed by the Rome III international working group on functional gastrointestinal disorders (shown in
Table 3-1) proposed that patients be classified based on stool characteristics as IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), IBS mixed type (IBS-M), and IBS unsubtyped (IBS-U). IBS is a prevalent condition with 7% to 10% of the population estimated to have the…