The expelled product is commonly called a stool or a bowel movement. Feces are normally brown or dark brown in color, soft, and formed.
Bile pigments give feces their characteristic color.
The typical odor is caused by nitrogen compounds that are produced by the action of bacteria. Medical examination of the feces for abnormalities is important in the diagnosis of certain disorders of the intestinal tract. The presence of blood in the feces may make them either black or bright red in color. This can occur because of infection, ulceration of the intestine or stomach, diverticular disease, malignant or nonmalignant tumors, abrasive foreign bodies, fissures, or hemorrhoids. Pale yellow or white feces suggest a disorder of bile production, usually an obstruction of the bile ducts.