Sayyiduna Imran bin Husain (may Allah be pleased with him) narrates that I had hemorrhoids, so I asked the Prophet (peace and blessings of Allah be upon him) about how to perform the prayer. He (peace be upon him) said: "Pray standing; if you are not able to stand, then pray sitting; and if you are not able to sit, then pray lying on your side." In the narration of Muhammad bin Isa, the word "bawasir" (hemorrhoids) is used instead of "nasoor" (fistula)—(the meaning is the same).