Herbal supplements.

Herbal dietary supplements are taken by many individuals, often without the knowledge of their clinicians. Herbals have many pharmacologic and medicinal properties but are unregulated with respect to manufacturing purity, safety, and efficacy. Although clinicians often dismiss the utility of herbal therapy, many randomized controlled trials of herbal use in gastrointestinal and liver diseases have been conducted. There is no evidence for benefit from herbal supplements in the treatment of liver disease, but sufficient evidence exists for their use in functional gastrointestinal symptoms to warrant further investigation.