Defecation and Dyssynergic Defecation

Defecation is the process of removing solid or semisolid waste materials from the digestive tract. Whether the process is voluntary or involuntary, it increases the pressure in the intrarectum and produces pain. If the muscles involved in defecation aren’t relaxed during the bowel movement, the stool may not move correctly. This condition is known as dyssynergic defecation.

Defecation is a process of eliminating solid or semisolid waste materials from the digestive tract

Defecation is the removal of solid or semisolid waste materials through the body’s bowels. This process takes place a few times daily or once a week and is controlled by muscular contractions. In the human body, feces pass through the colon through the opening called the anus. As the fecal material enters the colon, it is absorbed by the water in the bloodstream and moves through the rectum to the anus.

The digestive tract consists of four parts, including the large intestine. The large intestine begins by processing wet waste from the ascending colon. This waste is separated from water, salt, and bacteria and is turned into a semisolid material called stool. This portion of the digestive tract is longer than the small intestine and has a wider diameter than the small intestine.

It can be involuntary or under voluntary control

Defecation can be involuntarily or under voluntary control. Young children learn voluntary control through toilet training and can defecate spontaneously. Other causes of loss of control may be bodily injuries, neurological impairments, or psychological issues. Some diseases affect water absorption in the colon. Defecation can be embarrassing and accompanied by urination.

The internal anal sphincter is a muscle that prevents continuous fecal passing. It is controlled by the pudendal nerve, which is part of the somatic nervous system. However, defecation can also be voluntarily controlled by the conscious or subconscious mind. When defecation is triggered by an impulse in the brain, it does not reach the conus medullaris of the spinal cord.

It causes increase in intrarectal pressure

The intrarectal pressure is increased when you defecate, and the fecal matter fills the rectum ampulla. The material fills the rectal walls, causing them to expand and fecal material to enter the anal canal. As the material fills the rectum, peristaltic waves propel the fecal matter out through the rectum, along with a portion of the urine. The pelvic diaphragm and external anal sphincters help prevent the anal canal from prolapsing during defecation.

Anorectal manometry can quantify the pressure in the anal space during defecation. This procedure can also be used to measure rectal compliance, which is the ability of the rectum to distend. The higher the compliance, the lower the resistance to distention. Defecation index is usually higher than 1.5. When this value is below this number, the patient is suffering from dyssynergic defecation, and should seek medical attention.