These things are called villi. They're like little fold that helps increase the surface area to maximize the amount of digestion.
This is the inside of the small intestine. Here, enzymes and bile will digest what is left of the food into small molecules. 90% of digestion occurs here, and the wall of the intestine will absorb any nutrients and send it to the bloodstream.
The exiting of faeces from the anus concludes the digestive system.
After leaving the small intestine (light pink), whatever substance is left enters the large intestine (purply-brown). Here, water is reabsorbed into the body. Towards the end of the large intestine is the rectum which stores the faeces until it leaves the body through the anus.