"صَلِّ قَائِمًا, فَإِنْ لَمْ تَسْتَطِعْ فَقَاعِدًا, فَإِنْ لَمْ تَسْتَطِعْ فَعَلَى جَنْبٍ"
Narrated 'Imran bin Husain (RA): I suffered from piles. So I asked the Prophet (ﷺ) about the prayers. He said: "Pray standing; and if you are unable, (pray) sitting; and if you are unable, (pray) lying on your side." [Reported by al-Bukhari].