Asma' bint 'Umais narrated that the Messenger of Allah (S.A.W) asked her what they used as a laxative. She said:
"Shubrum" He said: "It is hot and too strong." She said:"Then I used Senna as a laxative." So the Prophet (S.A.W): "If there was anything that would have a cure for death in it, then it would have been Senna." (DE)
English reference (DE): Vol. 4, Book 2, Hadith 2081 (DE)
Arabic reference (DE): Book 28, Hadith 2225 (DE)