Topic Highlight
Copyright ©2014 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 14, 2014; 20(10): 2492-2498
Published online Mar 14, 2014. doi: 10.3748/wjg.v20.i10.2492
Melatonin for the treatment of irritable bowel syndrome
Kewin Tien Ho Siah, Reuben Kong Min Wong, Khek Yu Ho
Kewin Tien Ho Siah, Reuben Kong Min Wong, Khek Yu Ho, Division of Gastroenterology and Hepatology, University Medicine Cluster, National University Hospital, Singapore 119228, Singapore
Kewin Tien Ho Siah, Reuben Kong Min Wong, Khek Yu Ho, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
Author contributions: Siah KTH, Wong RKM and Ho KY contributed equally to this work.
Correspondence to: Khek Yu Ho, Professor of Medicine, Chief, University Medicine Cluster, National University of Singapore Tower Block, Level 10, 1E Kent Ridge Road, Singapore 119228, Singapore. khek_yu_ho@nuhs.edu.sg
Telephone: +65-67795555 Fax: +65-67794112
Received: October 28, 2013
Revised: December 17, 2013
Accepted: January 20, 2014
Published online: March 14, 2014
Processing time: 134 Days and 14.9 Hours
Abstract

Irritable bowel syndrome (IBS) is a common disorder characterized by recurrent abdominal pain or discomfort, in combination with disturbed bowel habits in the absence of identifiable organic cause. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone produced by the pineal gland and also large number by enterochromaffin cells of the digestive mucosa. Melatonin plays an important part in gastrointestinal physiology which includes regulation of gastrointestinal motility, local anti-inflammatory reaction as well as moderation of visceral sensation. Melatonin is commonly given orally. It is categorized by the United States Food and Drug Administration as a dietary supplement. Melatonin treatment has an extremely wide margin of safety though it may cause minor adverse effects, such as headache, rash and nightmares. Melatonin was touted as a potential effective candidate for IBS treatment. Putative role of melatonin in IBS treatment include analgesic effects, regulator of gastrointestinal motility and sensation to sleep promoter. Placebo-controlled studies in melatonin suffered from heterogeneity in methodology. Most studies utilized 3 mg at bedtime as the standard dose of trial. However, all studies had consistently showed improvement in abdominal pain, some showed improvement in quality of life of IBS patients. Melatonin is a relatively safe drug that possesses potential in treating IBS. Future studies should focus on melatonin effect on gut mobility as well as its central nervous system effect to elucidate its role in IBS patients.

Keywords: Melatonin; Irritable bowel syndrome; Pain; Sleep; Analgesia

Core tip: Irritable bowel syndrome (IBS) is a common disorder associated with significant disability and high social cost. This is partly due to lack of effective treatment with low side effects. Melatonin is a drug that was postulated to be a potential useful arsenal in battling IBS. Its role in analgesia has been recognized in several other fields of medicine. Several well-designed placebo-controlled trials in IBS patients had consistently showed improvement of abdominal pain when taking 3 mg of melatonin with no serious side effect. Future studies should examine the long term effect of Melatonin as well as its effect on central nervous system and gut motility.