The effect of barium on blood in the gastrointestinal tract.

The effect of various commercial barium sulfate preparations on blood coagulation, flocculation, and hemolysis was studied. There was considerable variation not only among different barium products but also among different concentrations of the same product. There is no good experimental evidence that barium enemas do stop bleeding. It is probably best to avoid the use of any enema in attempting to control major colonic bleeding; but if an enema is given for this purpose, a tap-water enema is better, as it contains no anticoagulants and is more effective in producing clot formation than most barium suspensions.