The Compendium of Bheḷa 6.16.15

6.16.15

kṛṣṇaṃ purīṣaṃ bhavati rūkṣaṃ kiṃcitsaphenilam | nityaṃ gāḍhapurīṣaś ca bhinnavarcāḥ punaḥ punaḥ ||

The stool becomes black, dry, somewhat frothy; / he has constantly hard stool, and repeatedly loose feces;