Wikipedia Article About Anise oil on Wikipedia By distillation the fruit yields the volatile oil of anise, which is useful in the treatment of flatulence and colic in children. It may be given as Aqua Anisi, in doses of one or more ounces, or as the Spiritus Anisi, in doses of 5–20 minims. The primary constituent of the oil (up to 90 percent) is anethole. It also contains methyl chavicol, anisic aldehyde, anisic acid, and a terpene.