The present invention provides an occlusive composition comprising: a) a poly(2-cyanoacrylate) monomer of the following formula (I): ##STR00001## wherein n.gtoreq.2 and R is an organic moiety; and b) a visualization agent. The present invention also provides a method for creating a solid mass in an ionic fluid-containing bodily cavity within a living organism, comprising delivering into the bodily cavity a clinically sufficient amount of an occlusive composition comprising a poly(2-cyanoacrylate) monomer of formula (I) and a visualization agent.