Compositions of iodobenzoic acid derivatives in filmforming materials for visualization of the gastrointestinal tract

Disclosed are x-ray contrast compositions for oral or retrograde examination of the GI tract comprising a polymeric material capable of forming a coating on the GI tract, said polymeric material having atoms containing polarizable electrons thereon, in combination with a divalent cation; and an x-ray contrast producing agent of the formulawhereinZ = H, halo, C1-C20 alkyl, cycloalkyl, lower alkoxy, cyano, where the alkyl and cycloalkyl groups can be substituted with halogen or halo-lower-alkyl groups;R = C1-C25 alkyl, cycloalkyl, or halo-lower-alkyl, optionally substituted with halo, fluoro-lower-alkyl, aryl, lower-alkoxy, hydroxy, carboxy, lower-alkoxy carbonyl or lower-alkoxy-carbonyloxy, (CR1R2)p - (CR3 = CR4)mQ, or (CR1 R2)p - C ≡ C - Q;Ri, R2, R3 and R4 are independently lower-alkyl, optionally substituted with halo;x is 1-3y is 1-4;n is 1-5;m is 1-15;p is 1-10; andQ is H, lower-alkyl, lower-alkenyl, lower-alkynyl, lower-alkylene, aryl, or aryl-lower alkyl; in a pharmaceutically acceptable carrier and a method of its use in diagnostic radiology of the GI tract.