When seving as prime minister under the King Hui of the state of Qin. Zhang Yi had a carbuncle on his back.

He invited the famous doctor Sheng Gou to the state of Qin to cure his carbuncle and said to him, "Now treat my back as your own back. You can do whatever you think is right to treat my carbuncle."

Sheng Gou had cured the carbuncle of King Xuan before, and was a skilful doctor. Hearing what Zhang Yi said, the doctor felt no pressure at all. So he selected the right medical method according to his experience, and cured Zhang Yi as expected.

张仪在给秦惠王做国相的时候，背上长了一个大疮。

为了治好病，他特地请来秦国的著名医生竘，并对他说：“我这背现在已经不是我的背了，您认为怎么办合适就怎么治吧。”

竘曾经给宣王治疗过痔疮，医术高超，听了张仪这番话，心头的压力一下子就没有了。根据经验，他选择了合适的医疗方案，果然很快便治好了张仪的病。