Purgative Herbs  

Purgative herbs either stimulate or lubricate the large intestines to promote bowel movement.  They are mainly indicated in constipation.  Through the function of purgation, impacted feces and fluid remaining in the intestines are discharged, pathogenic heat or cold dispelled and edema relieved.

Based on their functions and indications, the herbs are divided into three classes: herbs that purge feces, herbs that lubricate intestines and herbs that transform water.

Notes in application:

a)  When interior syndrome occurs with exterior syndrome, these herbs are used with herbs that release the exterior syndrome.  Alternatively, herbs that release the exterior are given first, then the herbs that treat the interior syndrome.

b)  When body resistance (anti-pathogenic factor) is weak, these herbs are used with tonifying herbs.

c)  These herbs should be used with caution during weakness of the body due to chronic disease, during menstruation, pregnancy and after delivery.

d)  Since the herbs induce diarrhea, they should not be used once the bowel movement has become normal.  

a)    Herbs That Purge

Herbs that purge cause diarrhea.  They are bitter and cold in property, and function to reduce fire and promote bowel movement.  They are indicated in retention of feces due to accumulation of excessive heat in the stomach and intestines.  They are often used with herbs that promote Qi circulation and with herbs that clear heat and drain feces downward.  

b)    Herbs That Lubricate the Intestines

These herbs are mostly seeds of plants which contain oil that lubricates the intestines and moves the stool.  They are indicated in constipation due to deficient body fluids in an aged person or weakness of the body due to chronic disease.  This category of herbs is often used in combination with herbs that nourish blood or promote circulation of Qi, so as to strengthen the function of lubricating intestines for normal bowel movement.

c)   Herbs That Transform Water

These herbs purge water.  They cause the discharge of water, together with feces, from the body.  Some of these herbs promote urination and are indicated in cases with edema in the limbs, ascites, fullness in the chest and asthma due to phlegm-dampness.

These herbs are toxic; overdosing or prolonged administration is very harmful to the health.  When symptoms are relieved, the herbs should be stopped.