Try to describe the etiology and pathogenesis of constipation.

(2) Stagnation of Qi Constipation due to residue staying inside instead of going down which is caused by the stagnation of Qi, and the functional disorder of stomach and intestines in digestion, descent and transport resulting from melancholy and worry,or from lack of movement during prolonged sitting.

(3) Deficiency of Qi and blood Deficiency of Qi and blood often results from overstrain, or illness or senility. The deficiency of Qi can cause the dysfunction of the intestines in transport, while that of blood and body fluid can cause failure in moistening the intestines. Thus follows the difficulty in defacation.

(4) Accumulation of Y/n-cold difficulty in defecation due to the accumulation of Yin-cold caused by the deficiency of genuine-Yang(kidney-Yang) and the dysfunction of the kidney resulting from weakness, or senility.

How do you use purgative therapy correctly for treating constipation?

Purgation should be used as the main method for treating constipation, but purgatives can not be used singly. It should be used together with other drugs which are chosen according to the pathogenesis. The treatment of excess-syndrome should be aimed at clearing away heat and nourishing the intestines,promoting the circulation 0f Qi and dispersing stagnation; the treatment of deficiency-syndrome should be aimed at tonifying Qi and nourishing blood, eliminating constipation by using ,some warm-natured purgatives.

How many types is the constipation commonly classified into? What are the key points of differentiation, therapeutic principles and recipes for each type?

Heat-type

[Main points of differentiation] Dry stool,fever,deep-coloured urine, distending pain in the abdomen.

[Treatment] Clearing away heat and moisturizing intestines.

[Recipe] Via Zi Ren Wan

Stagnation of Qi

[Main points of differentiation] Dry and hard stool, desire for defecation but nothing defecated, frequent belching, feeling of fullness and oppression over the chest and hypochondria.

[Treatment] Promoting the circulation of Qi and dispersing, stagnation.

[Recipe] Liu Mo Tanl

Deficiency syndrome

(1) Qi-deficiency

[Main points of differentiation] Defecating with great efforts,

Sweating, shortness of breath, fatigue, timidness, feeble pulse.

[Treatment] Tonifying Qi and moisturizing the intestines.

[Recipe] Huang Qi Tang

(2) Blood-deficiency

[Main points of differentiation] Dry and hard stool,pale complexion, pale tongue and lips,thready pulse.

[Treatment] Moisturizing dryness by nourishing blood.

[Recipe] Run Chang Wan

Clod type (Yang-deficiency)

[Main points of differentiation] Difficulty in defecation,cold pain of abdomen, cold extremities.

[Treatment] Wanning Yang and relaxing bowels.

[Recipe] Ji Chuan Jian