The main function of the rectum is to act as a temporary storage site for fecal matter before it is eliminated from the body through the anal canal. As the food you eat passes through the digestive system, it is broken down and nutrients are absorbed in the stomach, small and large intestines. Fecal matter, which includes digestive juices, bacteria and fiber, continues to move into the lower portion of the large intestine -- the rectum. The rectum holds the feces until you push it out of the body, through the anal canal, by having a bowel movementPancreas secretes about 1 L of pancreatic fluid into duodenum which contains numerous enzymes that chemically digest carbohydrates, lipids and proteins.

Bile is a greenish-yellow fluid secreted by the liver that helps digest fat. It breaks the fat into fatty acids that can be utilized by the body and .It also acts as antioxidant, It removes bacteria and other toxins from liver which are transported outside the body along with the waste.Liver is the largest internal organ. In adult, it has a size of football with mass of 1.5 kg.The main functions of the liver is to process nutrients from food, make bile, remove toxins from the body and build proteins.

Ileum: 3 m long, contains smaller and fewer villi and they absorb the remaining nutrients. Roughly 7-5 feet in length, the ileum is the final section of the small intestine, linked to the large intestine by the ileocecal valve. The main function of the ileum is to absorb nutrients. Bile is also absorbed here and returns to the liver through blood vessels in the intestinal walls.

The large intestine is the thick, lower end of the digestive system, containing the appendix, colon and rectum. Its principle function is to reabsorb water and maintains the fluid balance of the body. Certain vitamins are also taken in through the large intestinal wall

The function of caecum is one end to the large intestine with the appendix(help fighting infection)

The function of colon is the water and minerals absorbed and the intestinal bacteria help in further breakdowns and absorption of the minerals left over is called feces.

Anal canal has 1.5 m long and has a larger diameter than smaller intestine. The end of intestine contains sphincters that control the time of excretion