Final answer:
Stomach enzymes that enter the small intestine mix with small intestine enzymes and do not return to the stomach. They are part of the digestive process until digested or excreted.
Step-by-step explanation:
During digestion, stomach enzymes may move into the small intestine where they would mix with enzymes from the small intestine itself. Enzymes such as pepsin from the stomach are inactivated by the bicarbonate in the pancreatic juice, and other digestive enzymes from the pancreas and intestinal wall take over the breakdown of nutrients. These stomach enzymes do not return to the stomach; instead, they continue to participate in digestion alongside small intestine enzymes until they are eventually broken down or excreted from the body as part of waste material. Moreover, the pancreas produces additional enzymes that are released into the small intestine to assist in the chemical digestion of proteins, fats, and carbohydrates.
It is important to note that the claim 'Bile emulsifies lipids in the small intestine' is correct, as bile acts on fats to increase their surface area, making it easier for lipases to break down the fats into absorbable fatty acids and glycerol.