What causes IBS?
Physiological factors implicated in the etiology of IBS symptoms include: visceral hypersensitivity to spontaneous contractions and to balloon distention of the bowel, autonomic dysfunction including exaggerated colonic motility response to stress and alterations in fluid and electrolyte handling by the bowel, and an alteration in the gastrocolonic response. However, alterations in these physiological parameters are generally found in only a subset of patients and frequently do not correlate with bowel symptoms. Behavioral factors such as stressful life events are reported by up to 60% of IBS patients to be associated with the first onset of the disease or with its exacerbation. Laboratory stressors have also been shown to affect gastrointestinal motility and visceral perception. Cognitive factors such as inappropriate coping styles and illness behavior are common in IBS patients and influence healthcare utilization and clinical outcomes. Emotional and psychiatric factors, such as anxi
