Generally, ordinary fiberoptic tracheoscopy can be eaten after 2 hours; while painless tracheoscopy usually takes 4~6 hours before eating. Lung fiberscope examination before the general need to fasting water, general fiberscope examination is generally given local anesthesia, after the end of 2 hours after you can start to eat food, drink water; painless bronchoscopy due to the use of general anesthesia drugs, will affect the patient’s swallowing function, so it is best to eat 4 ~ 6 hours after the examination. At the end of fiberoptic bronchoscopy, it is recommended to eat a liquid diet first, preferably with water, to see if choking occurs. Only when there is no choking can you start eating slowly. If there is a biopsy or other invasive operation during the operation and bleeding occurs, it is recommended not to eat food with high temperature so as not to aggravate the bleeding by vasodilatation, and a warm and cool diet should be used at this time. Consult your physician for specific precautions.