In general terms, egestion is the physiological process by which food not digested by the body is eliminated. Said elimination is done in the form of feces and constitutes the final phase of the digestive process.
Egestion in unicellular organisms includes only the expulsion of substances that cannot be used outside the cell. In multicellular organisms, as is the case of human beings, this process is more complex.
Sometimes egestion is confused with other similar processes, such as excretion. Although both are associated with digestion, these are different physiological processes. Let's see what they consist of.
The digestion process
The main function of the digestive system is to process food. The objective is to extract from them the greatest possible amount of nutrients and, at the same time, eliminate those substances that cannot be used and, therefore, must leave the body.
Digestion begins when food enters the mouth. In this phase, the saliva is mixed with the food and with it its decomposition process begins. What is formed with that combination is the bolus, which then passes into the esophagus and then into the stomach.
Subsequently, it reaches the small intestine. There, nutrients are separated and absorbed. Then, they are introduced into the bloodstream to reach the entire body. But nevertheless, Smaller and / or less soluble substances cannot be absorbed or used. This results in egestion.
What is egestion?
Egestion is the last function of the digestive system. The remains of undigested food in the small intestine go up the colon upward. There, a process of reabsorption of water and some elements, such as sodium, takes place. Likewise, folic acid and vitamin K are absorbed, for example.
The remaining remains continue the march through the transverse colon and then down the descending colon. There, they are stored in the form of stool. Then, this material goes to the rectum, which opens to the outside through the anus. Finally, defecation occurs.
This whole process is called egestion. Feces contain bacteria and fiber, as well as metabolic products from the liver and other materials that have not been used. The feces are expelled between 36 and 48 hours after the ingestion of food, under normal conditions.
Egestion and excretion
Sometimes egestion is confused with other processes, such as excretion. Although they have some similarities, the truth is that they are different physiological processes. Let's see how they differ from each other.
Egestion is the elimination of substances that came with food and that are not usable by the body. This includes non-digestible substances and material harmful to the human body. It corresponds to food that failed to enter the bloodstream and, therefore, must be eliminated in the form of feces.
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In excretion there is also elimination of substances. The difference is that the substances expelled in the excretion have been previously used by the body to maintain various vital functions. The process that takes place, in this case, occurs inside the cell.
Cells need energy to function and get it from nutrients. These arrive in the form of organic molecules, which are broken down by the cell to produce energy. At the end of that process, waste is produced, which is finally eliminated through the urine.
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Problems with egestion
Sometimes the egestion process is not carried out properly and some problems appear in the elimination of feces. This may be due to illness or improper diet. The most common problems are the following:
- Diarrhea. It occurs when watery and soft stools are removed. This occurs when the passage through the small intestine has been very short. Obey multiple causes.
- Fecal incontinence. It implies an absence of control over defecation. Usually, it results from a loss of control over the sphincters or intestines.
- Constipation. It is characterized by dry and hard stools, difficult to eliminate. There is talk of constipation when less than three bowel movements are made per week.
- Encopresis. It corresponds to the involuntary elimination of feces in children. There are multiple causes behind this problem.