fæces

Fæces, also spelled faeces, are the solid, excreted remains of digestion produced by humans and many other animals. They reflect material that has not been absorbed by the digestive tract, and typically consist of indigestible food matter, a large population of gut bacteria, shed intestinal lining cells, bile pigments, mucus, and trace amounts of fat and minerals.

Composition and characteristics vary with diet and physiology. In humans, water typically accounts for about 70–75 percent of stool, with the remaining dry matter composed of bacteria, dietary fiber, fats, proteins, and inorganic material. The color arises mainly from bilirubin breakdown products such as stercobilin, giving a range from light brown to deep brown. Odor is produced by volatile compounds formed by bacterial metabolism. Stool form is described by the Bristol Stool Chart.

Formation and elimination: fæces form in the large intestine as water is absorbed and microbial activity breaks down content. Peristaltic movements and the defecation reflex move stool toward the rectum for excretion. Stool analysis is used in medicine to diagnose infections, malabsorption, inflammation, and other conditions; the presence of blood, fat, or pathogens can be clinically significant.

Ecological and social aspects: agricultural use of fæces as manure, risks of pathogen transmission in sanitation systems, and public health measures emphasize proper disposal through toilets and sewage treatment or composting. The term fæces derives from Latin faeces, related to dregs or sediment.