The Effect of Fluoxetine in Patients with Pain and Constipation Predominant Irritable Bowel Syndrome

Abstract

Background: Irritable bowel syndrome (IBS) is the most common disorder diagnosed by gastroenterologists seen in about 40-50% of patients seeking care from a specialist. IBS has been treated with selective serotonin reuptake inhibitors, but there is not enough evidence from controlled trials for their effectiveness.

Materials and Methods: The aim of the study was to compare the effects of fluoxetine and placebo in the treatment of pain and constipationpredominant IBS in a double-blind randomized controlled trial. Forty four cases meeting Rome II criteria for IBS with predominance of pain and constipation were included in this study. Organic causes were ruled out by detailed history, physical examination, laboratory tests, and colonoscopy. Participants were then randomly assigned to receive either fluoxetine or placebo for 12 weeks. Subjects were followed using a simple symptom score system during treatment and four weeks after termination of treatment.

Results: Fluoxetine was significantly more effective than placebo in decreasing abdominal discomfort, relieving feeling and sense of bloating, increasing frequency of bowel movements and decreasing consistency of stool. The total symptom score decreased from 10.7 to 2.8 in the fluoxetine group vs. 10.5 to 6.7 in controls (p‹0.001).

Conclusions: Fluoxetine is an effective and well-tolerated short-term treatment for pain and constipation-predominant IBS.