A preliminary study of melatonin in irritable bowel syndrome

J Clin Gastroenterol. 2007 Jan;41(1):29-32. doi: 10.1097/MCG.0b013e31802df84c.


Background and aims: Melatonin is involved in the regulation of gut motility and sensation. We aimed to determine if melatonin was effective in improving bowel symptoms, extracolonic symptoms, and quality of life (QOL) in irritable bowel syndrome (IBS) patients.

Methods: Eighteen patients (aged 18 to 65 y; 6 females) were randomly assigned to receive either melatonin 3 mg (n=9) or matching placebo (n=9) at bed time for 8 weeks. The overall IBS scores, extracolonic IBS scores, QOL scores were assessed at 2, 4, 6, and 8 weeks during treatment and at 16, 24, and 48 weeks during follow up.

Results: Compared with placebo, melatonin taken for 8 weeks significantly improved overall IBS score (45% vs. 16.66%, P<0.05). The posttreatment overall extracolonic IBS score was significantly lower (49.16% to 13.88%, P<0.05) when compared with placebo group. The overall improvement in QOL score was 43.63% in melatonin group and 14.64% in placebo group that is statistically significant.

Conclusions: The result of this study showed that melatonin has some beneficial role in IBS. Further studies using large number of patients may provide a definite answer.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Free Radical Scavengers / therapeutic use*
  • Humans
  • Irritable Bowel Syndrome / drug therapy*
  • Male
  • Melatonin / therapeutic use*
  • Middle Aged
  • Treatment Outcome


  • Free Radical Scavengers
  • Melatonin