What is role of the pancreas in diabetes?
After your body has finished digesting the pizza, your blood sugar levels will be high since the small intestine has absorbed the sugars from the starches that were present in your meal.  The pancreas recognizes the increase in blood sugar and it begins to release insulin into the blood stream.  Insulin acts as a gatekeeper for your cells by regulating the flow of glucose into them.  Glucagon, on the other hand, functions opposite of insulin.  Your liver and muscles store the excess glucose in your blood as glycogen.  Whenever your brain senses that blood sugar levels are too low, it triggers the pancreas to release glucagon.  Glucagon also serves as a gatekeeper for your cells, triggering cells in your liver and muscles to change glycogen to glucose and to release it into the blood stream until the blood sugar level has returned to normal.  

People with diabetes do not make enough insulin in their pancreas.  As a result, blood sugar rises. Cells are being starved for sugar because the sugar can't get into cells and stays in the blood.  Excess blood sugar also dehydrates cells, because they lose water by osmosis. Click here to review osmosis.

What does the large intestine do?
The large intestine's main function is to extract fluid and salts.  The large intestine removes the salt by actively transporting sodium (Na⁺) ions out of the large intestine and into the blood vessels (see graphic). Chloride (Cl^-) ions are passively absorbed by the pull of positive electrical charge caused by removal of Na⁺.  

Water flows out of the large intestine with the removal of salt due to osmosis, since the blood has a higher concentration of particles than the large intestine.  Water diffuses towards the particle rich blood. 

If excretion of the wastes is delayed, constipation may occur.  When the wastes are retained in the large intestine, large amounts of water will be absorbed by the body, leaving the wastes firm and dry.  In contrast, diarrhea is characterized by a highly fluid waste that is caused by an inadequate amount of water absorption by the intestine.  Diarrhea can be caused by increased intestinal movement due to bacteria, virus, or stress, an increase in osmotic particles in the wastes that prevents water from escaping into the blood, or toxins released by cholera bacteria or other microorganisms that increase the secretion of excessive amounts of fluid by cells in the intestine. 

You have your own fermentation vat in your gut. The large intestine is the home of several types of bacteria, but in the large intestine these bacteria are not harmful to your body. Instead, they are critical to the digestive process.  These bacteria produce vitamin K, used in blood clotting. The bacteria also breakdown certain carbohydrates that your body can't break down with its enzymes. The bacteria also cause gas. Know what I mean?

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