The effect of fluoxetine in patients with pain and constipation-predominant irritable bowel syndrome: a double-blind randomized-controlled study.

BACKGROUND

Irritable bowel syndrome has been treated with selective serotonin reuptake inhibitors but there is not enough evidence from controlled trials to prove their effectiveness.

AIM: To compare the effects of fluoxetine and placebo in the treatment of pain and constipation-predominant irritable bowel syndrome in a double-blind randomized-controlled trial.

METHODS

Forty-four cases meeting Rome II criteria for irritable bowel syndrome 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. Symptoms addressed by the Rome II criteria were recorded during treatment and 4 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. Mean number of symptoms per patient decreased from 4.6 to 0.7 in the fluoxetine group vs. 4.5 to 2.9 in controls (P < 0.001).

CONCLUSIONS

Fluoxetine is an effective and well-tolerated short-term treatment for pain and constipation-predominant irritable bowel syndrome.