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.
One important difference between communicable and non-communicable disease is that non-communicable diseases tend to be chronic, which means they last a long time and progress slowly. Communicable diseases are more likely to be acute, which means the disease develops quickly.
The boundary between contagious and non-contagious infectious diseases is not perfectly drawn, as illustrated classically by tuberculosis, which is clearly transmissible from person to person, but was not classically considered a contagious disease.he non-contagious category of infections usually require a special mode of transmission between persons or hosts. These include need for intermediate vector species (mosquitoes that cause malaria) or by non-casual transfer of bodily fluid (such as transfusions, needle sharing or sexual contact).