Table 2.

Placebo-controlled studies: side effects of melatonin in irritable bowel syndrome patients

Ref.	Subjects (total, age, IBS criteria)	Dosage, frequency, duration	Sleepiness	GI side effect	Others
Lu et al[26], 2005, Singapore	17, 41+/-14 years old woman, ROME II IBS	3 mg bedtime for 8 wk	1 × Daytime sleepiness (both treatment and placebo group)	Nil	Nil
Saha et al[27], 2007, India	18, 18-65 years old, ROME II IBS	3 mg bedtime for 8 wk	1 × Drowsiness (both groups),	Nil	1 decreased libido
Chojnacki et al[72], 2013, Poland	80, 48-65 years old woman, ROME III IBS	3 mg morning, 5 mg bedtime for 6 mo	Nil	Nil	2 fatigue, 1 vertigo

IBS: Irritable bowel syndrome; GI: Gastrointestinal.