It is narrated from Sayyiduna Imran bin Husayn (may Allah be pleased with him) that a man came to the Prophet (peace and blessings be upon him) with his brother, who was suffering from dropsy (a disease in which water collects in the abdomen). He said: O Messenger of Allah, my brother's abdomen has filled with water; I took him to the physicians and they advised me to cauterize him. Shall I cauterize him? The Messenger of Allah (peace and blessings be upon him) said to him: "Do not cauterize him," and sent him back to his family. Then a camel passed by him and struck him on his abdomen, and his abdomen went down. He was brought to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Had you taken him to the physicians, you would have said that the fire cured him."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15424