The son of Duan Zhailang, four years old, suffered from coughing, fever, expectoration of phlegm, and hemoptysis after several days. Previous physicians treated him with Jiegeng Tang (Platycodon Decoction) and Fangji Wan (Stephania Pill), but the condition did not improve. Phlegm-saliva attacked upward, causing incessant vomiting and wheezing. Qian Yi was consulted. He administered a large dose of Xiabian Yin Wan (a purgative pill for expelling phlegm) and subsequently treated the patient with Bufeitang (Lung-Supplementing Decoction) and Bufe San (Lung-Supplementing Powder). Someone asked: "The child of the Duan family has hemoptysis and lung deficiency; why use a purgative method?" Qian replied: "Although there is hemoptysis due to lung involvement, it is caused by heat. If prolonged, it will lead to deficiency and flaccidity. Currently, phlegm-saliva surges upward causing vomiting; one must first purge the phlegm-saliva,"