Liushui Tang (Flowing-Water Decoction) for Deficiency-Irritability Insomnia
The Waitai Miyao includes a formula called Liushui Tang (Flowing-Water Decoction), originally collected in the Xiaopin Fang, which Wang Tao of the Tang dynasty incorporated when compiling the Waitai Miyao. Its composition is: Banxia (Pinellia) 2 qian (6 g), Jingmi (round-grain rice) 9 qian (27 g), Fuling (Poria) 4 qian (12 g). To prepare, slice the Banxia and Fuling into pieces; use about 1.2 liters of east-flowing water, agitate it three thousand times until turbulent, then decoct the herbs to about 500 ml, strain, and take warm in five divided doses. This formula nourishes the heart and calms the spirit, harmonizes the stomach and resolves irritability; it treats deficiency-irritability with inability to sleep.
Jingmi (round-grain rice) is an oily rice that makes sticky cooked rice and porridge. In the countryside, New Year cakes were traditionally made mainly from it. Though less nutritious than brown rice, jingmi is rich in starch, protein, fat, fiber, vitamins, and trace elements. TCM holds that jingmi fortifies the spleen and stomach, supplements the center and boosts qi, strengthens tendons and bones, grows flesh and generates tissue, and quenches thirst and promotes fluids. In fact, jingmi does treat stomach disorders.
Given its composition, this is a formula for deficiency-irritability insomnia caused by reflux esophagitis or gastritis. TCM holds that "when the stomach is not harmonized, lying down is restless." Stomach-disorder patients often feel gastric emptiness and discomfort, which causes mental agitation and disturbs sleep. The Banxia in this formula downbears counterflow and stops vomiting, dries dampness and resolves phlegm, and is a common herb for gastric reflux. Fuling fortifies the spleen and stops diarrhea, drains water and reduces edema, and nourishes the heart and calms the spirit; it is a key herb for spleen deficiency with water-dampness.
Combining Banxia and Fuling with jingmi makes a fine formula for harmonizing the stomach, resolving irritability, nourishing the heart, and calming the spirit. The requirement to repeatedly agitate east-flowing water—running water from rivers—before decocting comes from the ancients' discovery that running water gives better medicinal effects. As water flows, hydrogen bonds are constantly broken and reformed, giving the water better penetrating power: it enters cells more quickly, promotes cell metabolism faster, nourishes skin and mucous membranes, and improves digestion. Though lacking modern chemistry, the ancients discovered this law in practice, hence the requirement to use running water.
This formula looks simple, but its combined action is not simple. It works well for indigestion from digestive tract disease, and such patients often have poor sleep, so the formula treats insomnia caused by gastrointestinal discomfort.