The lining of the colon is different from the small intestine in that there exists a large number of mucous cells that do not secrete enzymes but rather mucous. The mucous helps protect the wall from the bacterial fermentation inside. About 1.5 L of liquid digestive contents, chyme, pass into the colon.
Communicable disease refers to diseases that can pass from one person to another. Non-communicable diseases occur in one person and cannot be passed on to another person. Communicable diseases are also known as infectious diseases, and non-communicable diseases are referred to as chronic.
In brief: Spread. A communicable disease is a disease many others may get and that is why we have vaccinations. A contagious disease is a disease someone in contact with the person may catch. An infectious disease is a disease that may be spread within the person such as a virus or a bacterial or a fungal infection. An infectious disease may be contagious and communicable but does not have to be. In brief: Spread.