How can the small intestine go into the large intestine?

First the main function of intestines is to digest the nutrients and minerals of food that we eat until to its last drop before it get out of our body. So, if it did not eat enough there will be no food to digest but still intestine will perform its function so, the big intestine will still digest and since there is no material that is available for digesting it digest the nearest part to it which is the small intestines that is why they say that the large intestines eat the small one