An in vitro investigation of barium meals.

A technique is described for the in vitro study of the interaction of barium sulphate suspensions, used as radiopaques, with rat ileum. The technique, which allows close approximation to the in vivo situation with accurate control of the experimental conditions, was shown to give reproducible results. The thickness of the radiopaque retained at the gut surface was related to the concentration of the suspension, but was not significantly affected by the pH of the suspension. Less viscous suspensions gave better coating of the gut surface. The nature of the stabilizing agent or the surface charge carried by the particles does not affect the adhesion of the particles to the ileal mucus.