About Oak bark
There are approximately 600 extant species of oaks. Oak bark is used as a tea for diarrhea, colds, fever, cough, and bronchitis; for stimulating appetite; and for improving digestion. The bark of the Oak tree has been used for treatment of diarrhea for a very long time. It is also is used to treat minor cases of cold, fever, bronchitis and cough. It is said that the saponin extracts found in the herb act as expectorant and help in releasing phlegm.
The herbal extracts of the tree are also applied topically to the skin for treating the following problems - inflammation or swelling of the skin tissues and genitals, mouth sores, hemorrhoids, eczema, leucorrhea, varicose veins etc. It also helps in reducing the symptoms of chilblains. Oak bark is also associated with the treatment of the following - internal hemorrhage, kidney stones, pneumonia and even cancer.