What is the process of expelling feces out body?

The process of expelling feces out of the body is called defecation. It is the final stage of the digestive process and involves the elimination of solid waste from the rectum and anus. The process is controlled by a combination of voluntary and involuntary muscle contractions, as well as nerve signals from the brain and spinal cord.

Here's an overview of the process of defecation:

1. Accumulation of Feces: After digestion and absorption of nutrients from food in the small intestine, the remaining undigested material, along with water, forms feces in the large intestine (colon). The colon stores the feces and allows for further absorption of water and electrolytes, making the stool more solid.

2. Rectal Filling: As the feces accumulate in the colon, the rectum, the final part of the large intestine, begins to fill. This stretching of the rectum triggers the urge to defecate.

3. Relaxation of Anal Sphincter: Defecation starts with the relaxation of the anal sphincter muscles. The internal sphincter, which is involuntary, relaxes first, followed by the voluntary relaxation of the external sphincter. This allows the stool to pass through the anus.

4. Colonic Contractions: Once the anal sphincters are relaxed, the colon contracts to push the feces towards the rectum. These contractions are coordinated by nerve signals from the brain and spinal cord, as well as by the local enteric nervous system of the colon.

5. Expulsion of Feces: As the colonic contractions increase in intensity, they create pressure within the rectum, pushing the feces out through the anus. This process is assisted by additional voluntary abdominal muscle contractions.

6. Sensation of Relief: After the feces are expelled, there is a sensation of relief and a reduction in the urge to defecate. The anal sphincters then tighten again to prevent further leakage of stool.

The frequency and consistency of defecation can vary from person to person. Factors such as diet, fluid intake, lifestyle, and certain medical conditions can influence the regularity and characteristics of bowel movements.