The majority of food absorption occurs in the later two-thirds of the small intestine, the jejunum and the ileum. Water and water-soluble vitamins, however, are absorbed in the large intestine.

The colon extracts water and salts while forming feces. The colon also absorbs some nutrients that made it through the small intestine without being absorbed, but its main job is water and salt absorbtion. 

The primary purpose of the colon is to reabsorb water and salt (NaCl) in order to dehydrate the stool into a compact form for defecation. On average, the colon reabsorbs 1.5L of water per day and moves excreted sodium from the stool back into systemic circulation for further use. Inhibition of sodium reabsorption by the cholera toxin is what leads to severe dehydration and diarrhea seen in the disease.

The primary roles of the large intestine are water and electrolyte absorption. If this role is impeded by a pathogen, diarrhea results. Dehydration can also be a secondary effect of large intestine damage, and can lead to death.

The small intestine is primarily involved in nutrient absorption and chemical digestion. The stomach is involved in mechanical digestion, and some chemical digestion. The liver produces bile, which can be secreted to emulsify fats.

The posterior abdominal wall is the location of many organs, one of which is the transverse colon. This part of the colon brings waste from one side of the body to the other, and hangs along the posterior wall in the abdominal cavity.

The colon consists of a few main parts. The ascending colon is the first region of the large intestine, connecting it to the small intestine. The ascending colon transitions into the transverse colon, which then becomes the descending colon. The descending colon transitions into the muscular sigmoidal colon, which terminates in the rectum.

The colon consists of a few main parts, including the ascending colon. The ascending colon is the first region of the large intestine, connecting it to the small intestine. The ascending colon transitions into the transverse colon, which then becomes the descending colon. The descending colon transitions into the muscular sigmoidal colon, which terminates in the rectum.

The myenteric interstitial cells of Cajal act as the "pacemaker" of the gastrointestinal tract. They cause spontaneous smooth muscle cell contractions in the stomach, small intestine, and large intestine. These contractions play and integral role in mechanical digestion and motility of digestates.

The stimulus is spread to the gastrointestinal tract via gap junctions; however, the action potential does not originate from the junctions themselves and must be initiated by the cells of Cajal. Acinar cells are found in several regions and are defined by their clustered formation to form an exocrine gland. Acinar cells secrete pancreatic enzymes and saliva in the mouth. The cells of Cajal act via spontaneous depolarization and are not under the direct control of gastrointestinal neurotransmitters.

Diarrhea is a condition that causes living organisms to have loose bowel movements. This means that the bowel movements contain a high amount of liquid water. Recall that the main function of the large intestine is to reabsorb water back into the body. If there is a decrease in water reabsorption, then more water will be excreted via bowel movements; therefore, decreased water reabsorption in the large intestine will lead to loose bowel movements and, subsequently, diarrhea.

Most of the pathogens are not killed in the large intestine; they are killed in the acidic environment of the stomach. The E. coli found in large intestine function to release vitamins, such as vitamin B12. They do not participate in water reabsorption; lack of microbes (E. coli) in the large intestine does not cause diarrhea.

The large intestine contains a bacterium called Escherichia coli, or E. coli. It is not a pathogen, and instead participates in a symbiotic relationship with the human. E. coli actively synthesize and secrete essential vitamins such as vitamin B12 (required for proper functioning of the nervous system). Recall that the lumen (inside) of the large intestine does not contain any oxygen; therefore, a living organism that thrives inside the large intestine must be able to survive without oxygen. E. coli is a type of facultative anaerobe; this means that it can survive in oxygen rich conditions and in oxygen poor conditions (such as the lumen of large intestine). 

Ebola is a type of virus and is usually not found inside the large intestine. Ebola virus is very harmful because it causes hemorrhagic fever, a fatal disease that leads to excessive blood loss from the circulatory system.

The question states that chyme is a semifluid food mass that enters the intestines. Recall that this food mass will first enter the small intestine, where the majority of digestion will take place. In the small intestine, chyme contains large amounts of undigested nutrients. The small intestine will absorb most of the nutrients (carbohydrates, fats, and proteins) and will send the digested food mass to the large intestine.

In the large intestine, water and undigested nutrients are reabsorbed from the chyme. The remainder of chyme is considered waste and is excreted through the rectum; therefore, chyme will enter the large intestine after the small intestine and will mostly consist of water and waste products. Most of the water is reabsorbed and the remaining chyme (waste products and a small amount of water) is excreted.