Is melatonin involved in the irritable bowel syndrome?

There is a substantial evidence that large quantities of melatonin are produced in gastrointestinal tract, however, is still unclear which is the role of melatonin in digestive system in human physiology and pathophysiology. In the present study we investigated urinary excretion of a main melatonin metabolite, 6-sulphatoxymelatonin, in patients with irritable bowel syndrome (IBS). The investigation was carried out in 67 persons, both sexes, aged 20-45 years old who according to Rome III Criteria were diagnosed as sufferers of constipation (C-IBS, n=21 persons) or diarrhoea (D-IBS, n=24 persons) form of irritable bowel syndrome and as healthy subjects (K, n=22), matched for control.