It was narrated from Asma’ bint ‘Umays that the Messenger of Allah asked her: “What do you use as a laxative?” She said: “Spurge.” He said: “Hot, hot.” She said: Then I used senna as a laxative and the Prophet said: “If there were anything in which there is a cure for death, it would be senna.”
[Al-Tirmidhi; 6/254]