BEZOARS are relatively rare occurrences, and 73 to 90% of them are diospyrobezoars due to ingested unripened persimmons,* De Bakey and Ochsner1 reviewed the literature most thoroughly, adding cases of their own, and showed that more than 70% of phytobezoars occurred after the age of 30 and that 77% were found in men. Chont2 emphasized that children and Negroes are almost entirely immune to persimmon-bezoar formation.
Considerable speculation has revolved about the etiology of diospyrobezoar formation. It has been demonstrated that the pulp of the unripened persimmon fruit contains soluble shibuol, a phlobotannin, which under the influence of a weak mineral acid, such as hydrochloric acid, is converted into an adhesive coagulum cementing fragments of pulp, seeds, and peel together. As the fruit ripens, the shibuol is rendered insoluble so that coagulum formation is unlikely. It is the soluble shibuol which gives the unripened persimmon its astringent taste.