The acidity has risen to a degree at which ptyalin is inhibited, and while careful mastication and insalivation may allow considerable starch to be thus converted into maltose, ordinary habits of eating by healthy adults do not usually allow any considerable quantity of starch to be thus digested. So long as the starch does not ferment, reliance may be placed upon the amylolytic action of the pancreas and the subsequent inversion by the intestinal ferment. Unless there is stagnation in the stomach, the inevitable starch indigestion in hyperchlorhydria gives no particular trouble. So-called starch indigestion is usually carbohydrate fermentation and occurs by preference in hypochlorhydria in which there is literally, more opportunity for starch digestion in the stomach, than normal.

Fats are never digested in the stomach to a degree appreciable by ordinary tests. Thus, so-called fat indigestion, merely refers to rancidity of fats caused by microorganisms and is usually concomitant with putrefaction of proteins.