The persimmon-bezoar, a kind of phytobezoar which is caused by overeating the astringent persimmon fruit, is generally understood to develop as a result of conversion of soluble shibuol, a specific constituent of the astringent persimmon fruit, into insoluble shibuol by the effect of gastric hydrochloric acid. However, according to the present experiment, inasmuch as only soft flocks are formed when hydrochloric acid is added to a suspension of fine skin pieces of the persimmon fruit, such an explanation seems to be insufficient. The authors applied their theory of solidification of colloidal substances in living organism to this problem and succeeded in preparing in vitro a bezoar-like solid concrement using persimmon fruit.