body waste discharged from the intestine; called also
stool,
excrement, and
excreta. The feces are formed in the colon and pass down into the rectum by the process of peristalsis. When the rectum is sufficiently distended, nerve endings in its wall signal a need for evacuation, which is made possible by a voluntary relaxation of the sphincter muscles around the outer part of the anus.
The frequency of bowel movements varies according to the individual body make-up, type of intestine, eating habits, physical activity, and custom. Although one bowel movement a day is the average, a movement every 2 or 3 days may be considered normal. A balanced diet and an established routine can promote regular bowel movements.
Characteristics. Normally feces are soft and formed and brownish in color. An abnormality in color, odor, or consistency usually indicates a disorder of the intestinal tract or of the accessory organs of the digestive system. Black, tarry feces may indicate intestinal bleeding, especially in the upper portion of the tract. Some drugs, such as those containing iron or bismuth, can produce tarry feces. Bright red blood in the feces can indicate a wide variety of disorders ranging from
hemorrhoids to a malignancy of the rectum. Clay-colored feces result from an absence or deficiency of
bile in the intestinal tract, indicating obstruction of the biliary tract or decreased production of bile by the liver. Greenish-colored feces often accompany diarrhea, especially in infants, and may be caused by growth of certain bacteria.
Bulky, fatty feces with a foul odor are characteristic of
cystic fibrosis. Other causes of fatty feces include gallbladder disease, pancreatic disorders,
sprue, and excessive intake of fat in the diet. Feces containing large amounts of mucus often occur in
colitis and
irritable bowel syndrome.
The feces of a newborn, full-term infant is called
meconium. It is a dark greenish brown color, smooth and semisolid in consistency.
Disinfection. In many types of communicable diseases it is necessary to decontaminate the feces before they are flushed into the sewage system. Chlorinated lime, Lysol, or formalin may be used for this purpose. The contents of the bedpan used by the patient should be thoroughly covered with the disinfectant and allowed to stand for several hours. The contents are then disposed of in a hopper or commode, and the bedpan is rinsed and sterilized, preferably with live steam or by autoclave.
Observations. Because the characteristics of the feces can be of help in the diagnosis of various diseases, it is important to inspect the stool for color, consistency, odor, and number of stools per day. Abnormalities should be noted on the patient's chart or reported to the physician.
Specimens. A sample of feces (stool specimen) may be required as a diagnostic aid. The specimen should be collected in a bedpan and transferred into a sterile container, using a wooden spatula or tongue blade for this purpose. In order for certain types of intestinal parasites to be discovered in the feces, the specimen must be fresh and kept warm until examined in the laboratory. Microorganisms that may be detected include the typhoid and paratyphoid bacilli, the anthrax bacilli, and
Entamoeba histolytica, which causes
amebic dysentery. Specimens of the feces may be examined for occult (hidden) blood. This test is indicated when intestinal bleeding is suspected but the stools do not appear to contain blood when examined by gross inspection.