Descending
    Herbs which either stimulate or lubricate the bowels to facilitate the expulsion of stool are classed as Descending.
Constipation and sluggishness of the bowel causes gradual accumulation of toxins in the body leading to many diseases.
Descending herbs have the effect of activating the descending function of the bowels, clearing away Heat, purging Fire, dispelling retained fluid and reducing edema.
They are indicated for interior Heat syndromes of excess type marked by dry stool They are indicated for interior syndromes of Excess type marked by dry stool, constipation, food stagnation, accumulation of heat of excess type in the interior, edema and fluid retention. Descending drugs are divided into three types
1/ Lubricating Laxatives.
2/ Cooling Purgatives.
3/ Cathartic Hydrogogues.
Purgatives, and Cathartic hydragogues, especially the latter, have potent actions and exert prompt effects, but they are apt to result in impairment of the genuine Qi, The action of lubricating laxatives are mild and they do not have the disadvantage of causing impairment of the genuine Qi. When purgatives are considered, attention should be pain to the following, in cases of interior syndrome of excess type accompanied with exterior syndrome, usually the exterior syndrome should be treated first, or if necessary, interior and exterior syndromes are treated simultaneously. For patients with interior syndrome of excess type accompanied with Qi Xu, reinforcement with tonics as well as elimination with purgatives should be given in combination. Purgatives tend to cause impairment of the Stomach Qi, and therefore, they should be discontinued as soon as the symptoms are relieved. Overdosage of purgatives must be avoided.

1/ Lubricating Laxatives - These herbs lubricate the bowel. Most herbs of this type are seeds or nuts rich in oil, and have the effects of relieving dryness and loosening the bowels, softening the stool, and promoting bowel evacuation.
These herbs are suitable for constipation caused by deficiency of body fluid, Yin Xu and Blood Xu in patients who are elderly, weak, suffering from protracted illness or postpartum patients.

2/ Cooling Purgatives- Drugs of this type are bitter in flavour, cold in property and have effects of loosening the bowels and purging fire. They are effective for interior syndrome of excess type manifested as accumulation of Heat of excess type, dry stools and constipation. They are also effective for affection by epidemic febrile diseases with high fever, unconsciousness, delirium and madness, or for headache, blood- shot eyes, gum swelling and pain due to flaring up of fire. Purgatives are often used in combination with drugs for promoting the flow of Qi and heat clearing drugs to reinforce their actions of purgation and elimination of Heat. Chinese medicine says that there is no pain from the six FU organs when there is no obstruction. Since purgatives are usually potent in actions, they should be used cautiously for patients suffering from Vital energy deficiency after chronic illnesses and for the aged and the weak and for women who are in pregnancy, postpartum or menstrual period.
These herbs are used to treat constipation due to stagnation of fluids. They tend to have a harsh
nature and act to drive out excess moisture.  Drugs of this type have a
very strong purgative action and can cause serious diarrhea to discharge the retained body fluid with
stool. Some of them have diuretic action and are therefore effective for edema, hydrothorax and
ascites, and dyspnea due to retention of Phlegm and fluid. Because these drugs have toxicity,
overdosage should be avoided and attention should be paid to their processing, compatibility, usage
and contraindications. For patients with serious conditions, they should be dispensed, according to
the actual circumstances, in combination with tonics to achieve the result of purging out the
pathogenic factors and reinforcing the body resistance.

3/ Cathartic Hydrogogues. Herbs of this type have a very strong eliminating action, driving out excess retained water and stools. Some also have a diuretic action. They are useful for treating edema and fluid retention in the thoracic (pleurisy) or abdominal cavities (ascites).
These herbs have some toxicity and a harsh nature, so care should be used in prescribing them. Since they can injure Yin and Qi, often tonics are prescribed with them, to reinforce the body.