Excrement

Excrement refers to waste material discharged from the digestive tract of animals, most often feces. The term can also encompass urine and other bodily wastes, collectively known as excreta, but common usage treats excrement as solid waste. In many species, excretion is the final step in digestion, allowing organisms to remove unused and harmful substances.

Feces are mainly water, with indigestible fiber, bacteria, cells shed from the intestinal lining, mucus, and metabolic byproducts. In humans and many mammals, the pigment stercobilin gives a brown color; diet, gut transit time, and microbiota influence color, odor, and consistency, which can range from hard pellets to soft, formed stool.

Defecation occurs in the large intestine; water absorption concentrates waste, which is then expelled through the anus. Some animals produce feces as pellets, others as liquid or semi-solid material. Excretion timing varies with diet, health, and species.

Handling excrement carries health risks because it can harbor pathogens such as bacteria, viruses, and parasites. Adequate sanitation, hygiene, and separation of clean water from waste reduce transmission. Public health relies on toilets, sewage systems, and proper waste management.

Disposal and treatment range from basic pit latrines and composting to municipal wastewater treatment. Treated excreta, biosolids, and digestates are sometimes reused as fertilizer under safety guidelines. Inadequate handling can contaminate soil, water sources, and crops, with implications for public health and agricultural sustainability.