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 predominance of infectious diseases is shifting to non communicable or chronic disease. Non-communicable diseases (NCDs) include a range of chronic conditions, including cancer, diabetes, cardiovascular disease, hypertension, as well as Alzheimer's and other dementias. They are commonly thought of as diseases of affluence.