Hairy grass root should be thatch root, referring to the Chinese medicine leucaena root. Having an appendicitis surgery is usually allowed to drink water decocted with leucaena root, but it should be used under the guidance of physician’s diagnosis. Bai Mao Gen, sweet and cold in nature, has the efficacy of cooling the blood to stop bleeding (making the blood cool and moist, preventing bleeding), clearing heat and inducing diuresis. It can be used for blood-heat-induced vomiting of blood, nosebleeds, blood in urine, as well as fever-induced heartburn and thirst, jaundice due to damp-heat, edema and urination, and hot showers (burning and stinging pains during urination, accompanied by frequent urination and urgent urination, and discomfort of pulling on the abdomen) and astringent pains. There is no evidence to suggest that you cannot drink water decocted with leucaena leucocephala after appendicitis surgery. If you have the above symptoms after appendicitis surgery, you can take it appropriately, but you have to use it under the guidance of physician’s diagnosis. The efficacy of leucaena leucocephala is quite a lot, but it should not be taken by those who have bleeding, vomiting, excessive urination and no thirst due to deficiency and coldness. If you need to use the medicine, please use it under the guidance of a physician, do not take it blindly.