Astanga Hrudaya
श्यामं तीक्ष्णाशुकारित्वादतस्तदपि शस्यते । क्रूरे कोष्ठे बहौ दोषे क्लेशक्षमिणि चातुरे ॥ ५ ॥
by its properties like penetrating and quick action; Even this is best suited for patients who have hard bowels great increase of the doshas and who can withstand the fatigue (of purgation).
english translation
zyAmaM tIkSNAzukAritvAdatastadapi zasyate । krUre koSThe bahau doSe klezakSamiNi cAture ॥ 5 ॥
hk transliteration by Sanscript