how does small intestine help in digestion of fat?

Digestion of fats

Digestion of fats mainly occurs in the small intestine. The negligible amount of digestion of fats also occurs in stomach by gastric lipase. Digestive juices from two glands, namely the liver and pancreas mix with the food and digestive juices in the small intestine.

The liver produces bile juice which consist of bile pigments (bilirubin and bili-verdin), bile salts, cholesterol and phospholipids but no enzymes. Bile salts causes emulsification of fats, i.e.,breaking down of the fats into very small micelles and also activation of lipases. 

Digestion of fats by enzymes in small intestine:

The pancreas and small intestine both produce lipase which cause digestion of fat in the small intestine.Both pancreatic lipase and intestinal lipase work in a similar manner. But, pancreatic lipase perform major hydrolysis of fats. 

The hydrolysis of emulsified fats by lipase occurs in stages. First, the emulsified fats (emulsified triglycerides) are broken down into diglycerides and one molecule of fatty acid.  The diglycerides are further broken  into fatty acids and monoglycerides. The monoglycerides are finally broken down into fatty acids and glycero​. Thus, one triglyceride is broken down into three molecules of fatty acids  and one glycerol. Digestion of fats usually remains incomplete in small intestine . So, the final products other than fatty acid and glycerol could be monoglycerides, and sometimes also diglycerides and triglycerides