What it is:
This herb consists of the root and rhi- zome of Rheum palma- tum L., or Rheum tanguticum Maxim. ex Balf., or Rheum officinale Baill. (family Polygona- ceae).It is mainly produced in Qinghai and Sichuan pro- vinces. The herb is dug in the late au- tumn when the stem and leaves begin to wither, or in early spring before the plant begins to sprout, then dried and sliced. It is used unprepared, or stir-baked with wine, or carbonized, or after some other ways of processing.

Property:
Bitter in flavour, cold in property, acting on the spleen. large intestine, liver and heart channels.

Effects:
Purging heat, loosening the bowels, removing heat from the blood, clearing away toxins, promoting blood circulation and removing blood stasis.

Used for:
1. Constipation due to stagnation in the bowels. rhubarb is an essen- tial herb for internal stagnation and constipation, and as it is bitter in flavour and cold in property, it is especially effective for constipation due to accumulation of heat. For constipa- tion and abdominal pain with tenderness due to heat of excess type in the intestines, it is often used with mirabilite, immature bitter orange and magnolia bark, as in Major Decoction for Purging Down Diges- tive Qi(Da Chengqi Tang) and Minor Decoction for Purging Down Digestive Qi (XiaoChenqi Tang). For constipation due to accumulation of heat and impair- ment of yin, it is used with dried rehmannia root and scrophularia root, as in Purgative Decoction for In- creasing Fluid and Sustaining Qi (Zengye ChengqiTang). For constipation of cold stagnant nature due to deficiency of the spleen-yang, it can be used with dangshen and lateral root of aconite, as in Decoction for Warming the Spleen (Wenpi Tang). In addition, rhubarb can be used for dysentery, loose but unsmooth discharge of stool due to damp-heat in the intestines, often in combination with peony root, scute- llaria root and aucklandia root, an in Peony Decoction (Shaoyao Tang).

2. Hematemesis and epistaxis due to invasion of blood by heat, and blood- shot eyes, sore throat, gun swelling and pain and others due to flaring up of fire. It is often used with coptis rhizome, scutellaria root and cow-bazoare, as in Decoction for Purging Heart-fire (Xiexin Tang) and Bezoar Antitoxic Bolus (Niuhuang Jiedu Wan).

3. Sores, carbun- cles and other pyogenic infections due to noxious heat, and burns. At the early stage of cellu- litis on the back accompanied with constipation and forceful pulse, it is usually used with dahurian angelica, as in Pill More Precious Than Gold for Expelling Pathogenic Factors from Both Interior and Exterior(Shuangjie GuijinWan); for appendicitis with abdominal pain, it can be used with moutan bark and mirabilite,as in Rhubarb and Moutan Bark Decoction (Daihuang MudanTang). For burns and scalds, it is used with sanguisorba in equal amount, the fine powder of the two herbs being mixed with sesame oil and applied topically on the burns or scalds.

4. Postpartum abdominal pain due to blood stasis, mass in the abdomen,traumatic injuries,and syndrome of blood retention. For postpartum blood stasis with acute pain and tenderness in the lower abdomen, it is often used with peach kernel and ground beetle, as in Decoc- tion for Discharging Blood Clots ( Xia Yuxue Tang). For blood stasis in the liver and spleen with distended abdomen and superficial venous engorgement, it can be used with zedoary and Chuanxiong rhizome,as in Decoc- tion for Regulating the Yin System (Tiaoying Yin). For traumatic injuries with blood stasis in the hypochondrium and unbearable pain, it is often used with Chinese angelica and safflower, as in De- coction for Recovery and Activating Blood Circulation (Fuyuan Huoxue Tang). For the syndrome of blood retention due to accumulation of heat in the lower-jiao causing stagnation of blood and qi mani- fested as feeling of fullness causing rigidity in the lower abdomen, madness but normal urination, it is often used with leech and peach kernel, as in Decoc- tion for Attacking Blood Stasis in the Lower Abdomen (Didang Tang) and Decoction of Peach Kernel for Activating Qi(Taoren Chengqi Tang). In addition, rhubarb has the effect of removing damp-heat and cholo- gogue action to relieve jaundice, so it can be used for the treatment of jaundice and stran- guria. To relieve jaundice, it is often used with Oriental Wormwood Decoction (Yinchenhao Tang). For stranguria marked by dribbling and painful micturition, it is often used with manshurian aristo- lochia stem and plantain seed, as in Eight Health Restoring Powder (Bazheng San).

Dosage and administration:3-12g, decocted in water for an oral dose. For purgation, it is better to boil it later than other herbs, or to steep it in boiling water for an oral dose. The unprepared herb has drastic actions and the prepared herb has mild actions. For promoting blood circulation,it should be used stir-baked with wine and for hemostasis, the carbonized herb is preferred.

Precautions:
It should be given cautiously or prohibited for women during pregnancy, menstruation or breast feeding period.