Turkey rhubarb (Rheum palmatum) is a 2,000-year-old remedy for digestive problems. Its name comes from the trade route used exporting it from China; it is also known as Chinese rhubarb. It's typically consumed as a tea or taken in capsule form, sometimes in combination with other herbs that support its intended effect. In small doses, its tannic acid content treats diarrhea. In larger doses, its anthraquinone glycosides relieve constipation.
Use Roots and Stems Only
Though the roots and stems of the plant are edible, the leaves are poisonous. They contain a high concentration of oxalic acid.
The high concentration of anthraquinone will case severe cramping should you take too much. However, underdosing will result in constipation, though this may be the desired result if taken to combat diarrhea.
If you grow and process your own turkey rhubarb, the recommended dosage of powdered root is "3 to 30 grains" according to "A Modern Herbal" at botanical.com (see Resources). Within that range, the amount taken depends on the effect desired. If you purchase turkey rhubarb root, always use as directed on the packaging.
"A Modern Herbal" additionally quotes a September 1921 journal reporting the use of powdered turkey rhubarb root in treating acute bacillary dysentery: "The dose given has been 30 grains every two or three hours until the rhubarb appears in the stools. After a few doses the stools become less frequent, hemorrhage ceases, and straining and the other symptoms of acute general poisoning, which characterize the disease, rapidly disappear."
Turkey rhubarb root is not recommended for long-term use, as this may cause diarrhea-related electrolyte imbalances.
If you are taking Lasix (furosemide), do not take turkey rhubarb or any other stimulant laxative, as this may lead to potassium depletion.
Those taking cardiac glycosides should have their physician monitor them frequently for potential toxicity while also taking turkey rhubarb.
Pregnancy and Nursing
Anthraquinones can stimulate menses and cause uterine contractions. For this reason, women should not take turkey rhubarb root while trying to conceive or in their first trimester of pregnancy. Turkey rhubarb is contraindicated for the entire pregnancy and while nursing, due to the risk of passing it to the fetus or infant.
According to the September 1921 journal quoted by "A Modern Herbal," children were treated for acute bacillary dysentery with three 5-grain doses of powdered rhubarb with two hours separating each pair of doses. However, today turkey rhubarb root is entirely contradindicated for children under the age of 12.
If you have ulcers or colitis, or if you are experiencing intestinal obstruction, undiagnosed abdominal pain or any inflammation of the intestines, you should avoid turkey rhubarb; the irritating effect anthraquinones have on the digestive system will exacerbate these conditions. Similarly, you shouldn't take turkey rhubarb if you have a history of kidney stones or gallstones, of if you've had your gallbladder removed.
Turkey rhubarb root contains pigments which may affect the color of your urine, turning it red or bright yellow. This effect is harmless.