What does the rectum do in digestion?

The rectum plays a crucial role in the final stages of digestion, particularly in the process of defecation. Here are the main functions of the rectum in digestion:

1. Storage of Stool: The rectum serves as a temporary storage site for solid waste products known as stool. As waste material accumulates in the rectum, it triggers the urge to defecate.

2. Formation of Stool: The rectum helps in the formation and shaping of stool by absorbing water from the waste material. This process results in the semi-solid consistency of stool, making it easier to pass.

3. Defecation: The rectum is essential for the voluntary control and expulsion of stool from the body. When the urge to defecate is felt, the rectal muscles contract, and the anal sphincter relaxes. This coordinated muscle action allows for the release of stool through the anus.

4. Sensing Rectal Distension: The rectum contains sensory receptors that detect rectal distension or fullness. These receptors send signals to the brain, triggering the urge to defecate.

5. Maintaining Continence: The rectum and the anal sphincter muscles work together to maintain continence, preventing involuntary defecation. The internal anal sphincter muscle is involuntary, while the external anal sphincter muscle is under voluntary control.

Overall, the rectum is responsible for storing and expelling stool, and plays a crucial role in the elimination of solid waste products from the body. Dysfunctions or diseases affecting the rectum can impact the normal digestive process and lead to various gastrointestinal symptoms.