Disclosed are x-ray contrast compositions for oral or retrograde examination of the gastrointestinal tract comprising iodinated polymeric, water-insoluble beads having a particle size of from about 0.01 to about 1000.mu. wherein said iodinated polymeric beads comprise a polymer containing repeating units of the formula (I) ##STR1## wherein A is a repeating organic unit in the backbone chain of the polymer; and X is an organic moiety containing or iodinated eromatic group and a hydrophilic group, said moiety having an iodine content within the range of from about 40 to about 80 weight percent based or the molecular weight of X, in a pharmaceutically acceptable carrier comprising a cellulose derivative.