The root of the kuzu plant, a member of the legume family, is prized in Oriental Medicine as the traditional medicine of choice for digestive, and many other disorders, and as a premier cooking starch / thickener. It has been part of the cuisine of China and Japan for more than 2000 years!
The very starch that makes kuzu an outstanding jelling and thickening agent in cooking is also responsible for its medicinal action. Kuzu's complex starch molecules are able to enter the intestines and relieve over acidity, bacterial infection, and excess water/bloating. Also it relieve abdominal aching and intestinal irritation. Kuzu also contains a high concentration of naturally occurring plant flavonoids, which are powerful antioxidants that have the ability to inhibit the contraction of smooth muscle, thereby increasing blood flow to, and relieve cramping in, the intestines. These flavonoids give kuzu it's strong medicinal/healing effect on both the digestive and circulatory systems.
Here's more info. about Kuzu: http://www.morino-kuzu.com/en