In general terms, egestion is the physiological process by which undigested food is eliminated by the body . This elimination is carried out in the form of feces and constitutes the final phase of the digestive process.
Egestion in single-celled organisms includes only the expulsion of substances that cannot be used out of the cell. In multicellular organisms, as in 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, they are different physiological processes. Let’s see what they consist of.
The digestion process
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The main function of the digestive system is to process food . The objective is to extract as much nutrients as possible from them 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 mixes with the food and with this its decomposition process begins. What is formed with this combination is the food bolus, which then passes to the esophagus and then to the stomach.
Subsequently, it reaches the small intestine . There, the nutrients are separated and absorbed. Then they are introduced into the blood stream so that they reach the entire organism. However, larger 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. Undigested food debris in the small intestine ascends the ascending colon . 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 remains that still exist continue the march through the transverse colon and then descend through the descending colon. There, they are stored in the form of feces. Then, this material goes to the right , which opens to the outside through the anus. Finally, defecation occurs.
This whole process is called egestion . The feces contain bacteria and fiber, in addition to metabolic products of the liver and other materials that could not be used. Feces are expelled between 36 and 48 hours after 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. Corresponds to food that failed to enter the bloodstream and, therefore, must be eliminated in the form of feces.
In excretion there is also elimination of substances. The difference is that the substances expelled in the excretion have previously been used by the body to maintain various vital functions. The process that takes place, in this case, takes place inside the cell.
Cells need energy to function and obtain it from nutrients. These come in the form of organic molecules, which are broken down by the cell to produce energy. At the end of this process, waste is produced, which is finally eliminated through the urine.
Problems with egestion
Sometimes the egestion process is not carried out properly and there are some problems with stool removal. This may be due to illness or an improper diet. The most common problems are the following:
- Diarrhea . It occurs when loose, watery stools are removed. This occurs when the passage through the small intestine has been very brief. It obeys multiple causes.
- Fecal incontinence . It supposes 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.