With the aid of bioengineering expertise, a technological process has been evolved that makes it possible to achieve a fairly uniform gastric freeze of the intact canine stomach, with only small disparities in the temperature of thermocouples dispersed over the surface of the intragastric balloon. An ice crystal slush in 30% glycerol has a large cooling capacity and resists warming far more effectively than does the 80% alcohol coolant used in prior gastric freeze efforts. Liquid nitrogen is employed to cool the iceslush glycerol mixture, which is circulated at a minimum flow rate of 6 liters/min. Guide lines of a safe freeze have been defined, which include control of intraluminal balloon pressure during the freeze, heparin sodium to preclude mucosal necrosis, and delimitation of the length and depth of the balloon surface thermocouple temperature depression during the freeze. Significant gastric secretory depression to graded doses of histamine diphosphate was consistently observed at all levels of histamine dosage up to 6 months after the freeze, with a gradual return to prefreeze levels at 12 months.