Paroxetine - Controlled Release in the Treatment of Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) is an extremely common disorder in the U.S population, affecting somewhere between 9-22% based on community based studies. IBS has a chronic relapsing course and overlaps with other functional gastrointestinal disorders. It accounts for high direct medical expenses and indirect costs including a significant degree of absenteeism. Most studies have suggested that there is a slight predominance among women, especially those that have suffered some form of physical or sexual trauma. It has been estimated that up to 25-40% of patients seen by gastroenterologists' are affected by IBS, and that 70-90% of these patients may have a psychiatric comorbidity, most commonly major depression and panic disorder, but also including schizophrenia, double depression, dysthymia and alcohol abuse. Abdominal pain and disturbance of bowel habits characterize the symptoms of IBS in the absence of demonstrable structural pathology. The diagnosis of IBS relies upon clinical criteria alone, as there is no "gold standard" in laboratory findings. The diagnosis is dependent upon identifying characteristic symptoms, and then differentiating IBS from other structural bowel disorders. Previously, the diagnosis of IBS was based upon a consortium recommendation that examined and defined diagnostic criteria for over 100 functional gastrointestinal disorders. These criteria became the most definitive in the area of functional disorders and are referred to as the Rome Criteria. During the time since this consensus, these criteria have been modified, and in 1999 became the foundation for the second set of diagnostic criteria by consensus, now referred to as the Rome II criteria. The revised Rome II criteria include only the first part of the original criteria, but now require the presence of two out of three symptoms relating abdominal pain to bowel symptoms. We designed our study and a Randomized, double-blind, parallel-group, flexible-dose, placebo-controlled 12-week study.