Answer:
The pH of a stomach is more acidic as the enzymes found in the stomach work best in acidic environments while enzymes in the intestines work better at a more neutral pH - like 6-7 depending on the intestine.
The stomach has a pH between 1.5 and 3.5 generally and this is due to the cells in the stomach releasing hydrochloric acid. The low pH is useful for “unraveling” proteins making them easier to digest and killing bacteria and other pathogens.
In the small intestine, the enzymes that "work" there need an alkaline pH in order to have optimum working conditions. Strong acids (like hydrochloric) can end up damaging the lining of your intestine.
