1. A DIAGNOSTIC INDICATOR ION EXCHANGE COMPOUND FOR DETERMINING WITHOUT INTUBATION WHETHER THE PH OF GASTRIC JUICE IN A STOMACH IS ABOVE OR BELOW A PREDETERMINED PH VALUE, COMPRISING A NON-TOXIC, INSOLUBLE GRANULATED CATION EXCHANGE COMPLEX SYNTHETIC POLYMER RESIN CONTAINING FROM ABOUT 0.01 MILLIMOLE TO ABOUT 0.6 MILLIMOLE OF DISPLACEABLE NON-TOXIC THIONIN DYE IONS PER GRAM OF RESIN SO AS TO BE DISPLACEABLE FROM THE ION EXCHANGE RESIN PREDOMINANTLY BY THE IONS FROM FREE HYDROCHLORIC ACID SECRETED IN THE STOMACH, SAID DYE IONS BEING ABSORBED READILY FROM THE GASTROINTESTINAL TRACT AND BEING EASILY DETECTED BY THE DYE COLOR IN URINE OR BLOOD.