The walls of your digestive tract are made up of four layers of tissue. The innermost layer is a lining made of cells that are shed and replaced regularly in a healthy body. This lining can have different functions in different parts of the digestive tract. For example, the lining in the small intestine releases water and digestive enzymes, and it absorbs nutrients from the food you eat.
This lining also releases mucus throughout nearly the entire length of the digestive tract. This mucus does two things to help digestion:
It helps protect the digestive tract from being damaged by the harsh digestive juices
It lubricates the inside of the tract so that solids can pass through more easily.
If the lining or other layers of tissue in your digestive tract are infected, inflamed, or otherwise damaged, it can cause several problems.
