Compositions of iodoaniline derivatives in film-forming materials for visualization of the gastrointestinal tract

A method of carrying out x-ray examination of the gastrointestinal tract of a patient, said method comprises the oral or rectal administration to the patient an x-ray contrast composition comprising:

• a polymeric material capable of forming a coating on the gastrointestinal tract, said polymeric material having atoms containing polarizable electrons thereon, in combination with a divalent cation;
• and
• an x-ray contrast producing agent having the formula, or a pharmaceutically acceptable salt thereof ##STR19## wherein Z is H, halo, C.sub.1 -C.sub.20 alkyl, cycloalkyl, lower alkoxy, cyano, where the alkyl and cycloalkyl groups can be substituted with halogen or halo-lower-alkyl groups;
• R.sub.1 and R.sub.2 are independently H, C.sub.1 -C.sub.25 alkyl, cycloalkyl, acetyl or halo-lower-alkyl, wherein said C.sub.1 -C.sub.25 alkyl, cycloalkyl and halo lower-alkyl are optionally substituted with fluoro-lower-alkyl, aryl, lower-alkoxy, hydroxy, carboxy, lower-alkoxy carbonyl or lower-alkoxycarbonyloxy and said acetyl is optionally substituted with fluoro-lower-alkyl, aryl, lower-alkoxy, hydroxy, lower-alkoxy carbonyl or lower-alkoxy-carbonyloxy;
• n is 1-4;
• y is 1-4;
• and
• x is 1 or 2
• in a pharmaceutically acceptable carrier.