RESUMEN
In the irritable bowel syndrome gastrointestinal tract motility is disturbed from the esophagus to the colon, causing pain and altered function. When colonic motility is abnormal, the patient can experience either constipation or diarrhea in addition to abdominal pain and bloating. In constipated patients the postprandial colonic motility can increase normally after eating or the colon can remain motionless. Generally propagating contractions are absent in patients with constipation predominant irritable bowel syndrome. Propagating contractions are increased in frequency in patients with diarrhea, although the phasic contractions are decreased. Questionnaires discriminate between patients with structural disease such as ulcerative colitis and patients with functional disease, however they cannot differentiate between the different subgroups of patients with constipation predominant irritable bowel syndrome. Treatment strategies are beginning to focus on the underlying pathophysiologic abnormality.