Understanding the Causes of IBS

Recent physiological and psychosocial data have emerged to improve our understanding of IBS.

A biopsychosocial model of IBS involving physiological, emotional, cognitive, and behavioral factors is now felt to be involved in symptom generation.

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 anxiety and depression, are present in 40 to 60% of IBS patients seeking healthcare with increased prevalence in those patients presenting to tertiary referral centers.

IBS patients who have sought medical care are more likely to have abnormal psychological profiles, abnormal illness behaviors, and psychiatric diagnoses than patients with other medical illnesses.

Many thanks to Laura Zurawski & Dr. Anthony Lembo for this posting.

Click here to read more...

technorati tags: irritable , bowel , syndrome , ibs , causes, psychological , hypersensitivity