Source: Shanghan Lun (Treatise on Febrile Diseases).

Ingredients:
No.1  Baitouweng (Radix Pulsatillae) 15 g
No.2  Huanghai (Cortex Phellodendri) 12 g
No.3  Huanglian (Rhizoma Coptidis) 6 g
No.4  Qinpi (Cortex Fraxini) 12 g

Administration:
Decoct the above drugs in water for oral administration.

Actions: Clearing away heat and toxin, cooling and relieving dysentery.

Clinical Application:
This recipe is indicated for dysentery due to heat, marked by abdominal pain tenesmus burning sensation in the anus, pus and blood in the stool with blood exceeding pus in amount, thirst with desire for drinking, reddened tongue with yellowish fur, taut and rapid pulse. It is applicable to acute bacillary dysentery, chronic nonspecific ulcerative colitis, acute colitis and other diseases, which belong to excessive-heat syndrome. If functional disorder of qi occurs as the result of excessive accumulation of heat, manifesting severe abdominal pain and tenesmus, add Zhishi (Fructus Aurantii Immaturus) and Binglang (Semen Arecae) to promote the flow of qi. In case of much blood in stool, add Yinhuatan (Carbonized Flos Lonicerae) and Diyu (Herba Thymi) to remove toxin and cool blood.

Elucidation:
The syndrome is due to dominance of toxic heat in xuefen and should be treated by clearing away heat and removing toxin, cooling blood and relieving dysentery. As monarch drug, ingredient No. 1 is good at removing heat and toxin, cooling blood and relieving dysentery. No. 2 and No. 3 can help the monarch drug eliminate heat and toxin and dry dampness to stop dysentery, functioning as minister drug. No. 4 serves as adjuvant drug, which can clear away heat and dry dampness, and has astringent action.
  
Shaoyao Tang and this recipe both possess the action of clearing away heat, toxin and relieving dysentery. The former, with a compatibility of drugs able to clear away heat and those to regulate the flow of qi and blood, is fit for dysentery with excessive damp heat manifesting pus and blood in the stool and greasy yellowish fur. The latter, however, is composed totally of drugs with the effects of clearing away heat and toxin, cooling blood and relieving dysentery and fit for dysentery with excessive heat, which is characterized by pus and blood in stool, with blood exceeding pus in amount, and dry yellowish fur. Clinically they can be selected for application in accordance with the actual condition, used in or combination.

Cautions:
The syndrome mentioned here is usually severe and critical, therefore it is advisable to use the decoction of this recipe for enema besides oral application so as to enhance the therapeutic effect.