The present invention relates to mechanically hemostatic body-absorbable compositions having a putty-like consistency which demonstrate excellent water resistance. The compositions are useful as mechanical hemostatic tamponades for the control of osseous hemorrhage. The compositions comprise carboxymethyl cellulose and one or more compounds selected from polyhydroxy compounds, esters of polyhydroxy compounds, fatty acids, esters of fatty acids, and mixtures of the foregoing.