Compositions of iodophenoxy alkylene ethers for visualization of the gastrointestinal tract

A method of carrying out x-ray examination of the gastrointestinal tract of a patient in need of such examination which comprises orally or rectally administering to the patient an effective contrast producing amount of an x-ray contrast composition comprising:

• an x-ray contrast agent, or a pharmaceutically acceptable salt thereof, having the formula:
• ##STR18## wherein Z.dbd.H, halo, C.sub.1 -C.sub.20 alkyl, cycloalkyl, lower alkoxy, alkoxycarbonyl, cyano, where the alkyl and cycloalkyl groups can be substituted with halogen or halo-lower-alkyl groups;
• R.dbd.C.sub.1 -C.sub.25 alkyl, cycloalkyl, ##STR19## or halo-lower-alkyl;
• each of which may be optionally substituted with halo, fluoro-lower-alkyl, lower-alkoxy, lower-alkoxy carbonyl or lower-alkoxy-carbonyloxy, (CR.sub.1 R.sub.2).sub.p -(CR.sub.3 .dbd.CR.sub.4).sub.m Q, or (CR.sub.1 R.sub.2).sub.p --C.dbd.C--Q;
• R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently H or lower-alkyl, optionally substituted with halo;
• x is 1-4;
• n is 1-4;
• m is 1-5;
• p is 1-20;
• and
• Q is H, lower-alkyl, lower-alkenyl, lower-alkynyl, lower-alkylene, aryl, or aryl-lower alkyl,
• in an aqueous, pharmaceutically acceptable carrier, said pharmaceutically acceptable carrier comprises a surface active agent selected from the group consisting of cetyl trimethylammonium bromide, sodium lauryl sulfate, sodium heptadecyl sulphate, an alkyl benzenesulphonic acid, sodium butylnaphthalene sulfonate, sulphosuccinate, carboxylic esters, carboxylic amides, ethoxylated alkylphenols and ethoxylated aliphatic alcohols, sorbitan esters, polyoxyethylene alkyl ethers and polyoxyethylene sorbitan fatty acid esters;
• and examining said gastrointestinal tract by an x-ray producing apparatus.