Defecation is taboo as a subject for polite conversation, far more so than sex, but most of us nevertheless wonder what qualifies as normal and what stool reveals about health. Here are nine questions you may have had but hesitated to ask—and the surprising answers.
Despite all the advice about the importance of being regular, there is no normal routine. It varies from person to person. People eating a typical Western diet generally have two to twenty bowel movements a week, depending on the specific foods they eat and other factors. Good health does not require daily defecation. Some perfectly healthy people defecate only twice a week; others, several times a day.
Not necessarily. Constipation doesn’t refer to infrequent bowel movements, but rather difficulty in defecating. Other symptoms of constipation are bloating and discomfort, and the passage of small, hard, dry stool.
People on a Western diet produce about five to seven ounces of stool a day. Vegetarians produce much more, since they eat lots of fiber, which absorbs water and bulks up stool.
Typically, it takes food about three days to pass through the body—for those of us who consume a Western diet. For vegetarians, because of their high fiber intake, it takes about half that time.
Stool is three-quarters water. If there is too much water in it, stool will be soft. Too little water, it will be hard. One of the main functions of the colon is to absorb water. If waste moves quickly through the intestine, less water is absorbed from it, so the stool remains soft. If waste moves slowly, more water is absorbed, and stool will be hard. Fiber in the stool soaks up water like a sponge and makes feces softer and bulkier. A high fat content, often the result of digestive disorders, can make stool soft, sticky and yellow. A gastrointestinal infection can also cause diarrhea.
The normal odor of bowel movements comes from hydrogen sulfide and other compounds produced by bacteria in the colon. Some people have more of these bacteria. Foods high in sulfur (broccoli, cabbage and related vegetables) can produce a stronger odor.
Normal stool color ranges from pale to dark brown, because of pigments formed when intestinal bacteria break down bile. Constipation often makes stool darker, as can iron supplements, black licorice or Pepto-Bismol. Red or green foods can color stool.
Stool floats because it contains something less dense than water— gas. Floating stool was once seen as a sign of fat in the stool, caused by malabsorption, but this is not the case. Gas is produced by intestinal bacteria acting on undigested food, particularly beans and other vegetables and fibrous foods that contain types of sugars called oligosaccharides. Diarrhea can also temporarily produce floating stool.
A sudden change in bowel habits—not explainable by such factors as dietary changes, stress or travel—may be a sign of illness. Many medical conditions can affect stool. White or gray stool may indicate liver disease; dark or bloody stool can indicate internal bleeding, including hemorrhoids; tar-like black stool may be the result of gastrointestinal bleeding. Bright red blood may indicate hemorrhoids, but rectal bleeding may also be a symptom of more serious disease. Any unusual, painful or unexplained bowel symptom that persists for a week or more calls for medical evaluation.
The basic heart-healthy, anti-cancer, high-fiber diet—rich in fruits, vegetables, beans and whole grains—is also good for your digestive system. Insoluble fiber (found in whole wheat, apples, broccoli and related vegetables and berries) particularly contributes to digestive health, increasing fecal bulk, speeding transit time and making stool softer and easier to eliminate. If you increase your fiber intake, drink more fluid. Most people do not need laxatives and should not rely on them.