The disclosure relates to a polymer and compositions thereof.In particular, the disclosure relates to a polymer, as shown in Formula IX-Y-Z I Wherein Z is an ethylene-vinyl alcohol copolymer, Y is a linkage, X is a visualization agent. The polymer is soluble in the non-physiological solution and insoluble in a physiological solution.本公開涉及一種聚合物及其組合物。具體而言,本公開提供了一種聚合物,如式I所示,X-Y-Z I,其中,Z為乙烯-乙烯醇共聚物,Y為連接部,X為可視化劑部分。該聚合物在非生理溶液可溶且在生理條件下不溶。