Bowel movement

Bowel movement is the process by which solid or semisolid wastes are eliminated from the body of animals. Wastes move through the gastrointestinal tract by peristalsis, or rhythmic contractions of gastrointestinal muscle. As it moves to the anus, nutrients and water are extracted.

Higher mammals have control over the actual release of the solid or semisolid feces, while birds, for example, expel it as soon as possible, probably to minimize their weight.

An excessive amount or rate of bowel movements is diarrhea, while inadequate movement is constipation.

Straining during a bowel movement can produce the neurophysiological effect of a Valsalva maneuver.