便便 (Feces) is the solid waste product that is expelled from the digestive system of humans and many animals. It is composed of undigested food, bacteria, and cells shed from the lining of the intestines. The color, texture, and odor of feces can vary based on diet and health. The process of producing feces begins in the digestive system, where food is broken down and nutrients are absorbed. The remaining waste is then formed into feces and stored in the rectum until it is eliminated from the body through the anus. Regular bowel movements are important for maintaining overall health.