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.
Cancers are one category of non-communicable diseases that cannot be spread to others. Chicken pox and other conditions caused by viruses are communicable diseases. Non-infectious diseases involving the respiratory system are a class of non-communicable conditions.
Many people think that contagious and infectious diseases are one and the same thing but there are many significant differences between the two. Though as a general rule, every contagious disease is infectious, but, all infectious diseases are not contagious.