Gentian Root (Gentiana lutea)Gentian is purported to be useful for digestion problems such as loss of appetite, fullness, intestinal gas, diarrhea, gastritis, heartburn, and vomiting. It is also used for fever, hysteria, and high blood pressure. Some people use gentian to prevent muscle spasms, treat parasitic worms, start menstrual periods, and as a germ killer.