Bolus is the food that is mashed up in the mouth. After it is digested in the stomach, the food is called chyme.
bolus are more alkaline that chyme because it is exposed to alkaline saliva. The and saliva turn food into bolus. It is passed through the esophagus into stomach.
Chyme have high acidity content than bolus because it was exposed to hydrochloric acid in the stomach. chyme enters in to small interstine after digestion in the stomach.