The summary of digestive system is mouth, stomach, and small intestine
Intestinal cells absorb nutrient needed by body. The waste material that cannot be used by body is transferred to large intestine.
In lipid absorption, fatty acid reacts with bile salt to form an emulsion, and with glycerol, It is absorbed by villous. In villous, fatty acid is separated from bile salt, and it bonds glycerin to form lipid (phospholipid). Phospholipid is release into lymph system in the form of small spheres layered with protein (chylomicron) and then it is carried to venous.
Other nutrients, such as vitamin, mineral, and water; will be absorbed by capillary vessel. The remain bile salt will enter the blood, and then it is carried to liver to be converted into bile again.