What does the mucous do for the stomach?
Mucus protects the lining of the stomach from being digested by acid.
Hydrochloric acid (HCl) is present in the stomach to aid with digestion. HCl converts the inactive enzyme pepsinogen into its active form pepsin. Pepsin helps digest proteins in the stomach.
Without mucus, the acid in the stomach would eat away at the stomach lining. The acid is extremely corrosive and could cause great damage to the gastric cells and tissues.
To serve as a buffer against the acidic environment, mucus in the stomach contains bicarbonate, an alkaline (basic) compound.