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.

張儀在給秦惠王做國相的時候，背上長了一個大瘡。

為了治好病，他特地請來秦國的著名醫生竘，并對他說：“我這背現在已經不是我的背了，您認為怎么辦合適就怎么治吧。”

竘曾經給宣王治療過痔瘡，醫術高超，聽了張儀這番話，心頭的壓力一下子就沒有了。根據經驗，他選擇了合適的醫療方案，果然很快便治好了張儀的病。