A composition for forming a temporary intestinal occlusion in a mammal is flowable and solidifiable to form a solid plug at a predetermined site in the intestine, the structure of the plug being changeable to allow for a subsequent, at least partial removal of the occlusion. The composition is or comprises a flowable solution, suspension, or dispersion in a solvent or mixed solvent, and comprises the following: a) a suspension of a solid in water or an aqueous mixed solvent, the suspension having a water content which exceeds the flow limit of the suspension by a specific amount; b) a dehydrating agent in an amount which is sufficient to bind the specific amount of water, so that, as a consequence of dehydration, the flow limit of the suspension is exceeded; and c) a means for passivating the dehydrating agent.