The color of the bowel movement can assume many shades. A stool which has become nearly white or gray indicates a complete lack of bile coming from the liver-from which the normal stool color comes. In this event, jaundice, a yellow tint to the skin will probably soon be noticed to indicate serious disease in the liver region.
A black stool means that iron in the intestinal tract has been in contact with stomach acids and the most common reason for an inky black stool is the ingestion of iron in vitamins, tonics or other iron compounds. But if none of these medications have been taken, and the stool is still pitch black, its probable cause is bleeding in the stomach or intestinal tract. Blood hemoglobin also turns black after contact with stomach acids, and about three ounces of blood in the intestinal tract will supply enough iron to turn the entire stool black. With less than this amount, only a partly black stool is the result.
Red blood in the stool means bleeding from the lower intestine or colon. When the blood is mixed with the bowel matter, it is probably coming from a bleeding area within the upper colon, such as a growth or ulceration. When the blood appears only on the outside of the bowel movement as a thin covering, the most likely source of the bleeding is from the anal outlet, from such difficulties as hemorrhoids or fissure.
Occasionally, a stool will be found to float near the top of the water. This means that it contains more than the normal fat content in the stools, and is possibly due to an occasional meal containing too much fat which has rushed through the intestinal tract. Repeated stools that float, however, may mean a deficiency of digestive juices which should have digested the fat. This deficiency would point to the pancreas, whose faulty function is not supplying enough digestive juices.
Finally, the odor of the stools must be reckoned with. Odor of the stool is derived from the chemicals skatol and hydrogen sulfide. The psychology of the nose allows us a daily personal contact with our own bowel movement, without noticing its disagreeable odor. In disease however, when odors are arising from other than the usual bowel element, these intensified odors of the bowel movement may become immediately noted.
For each person, there develops over the years individual characteristics concerning the bowel movement and the stool itself. This is called the bowel habit, which, when noticeably and suddenly changed, especially in the over fifty age group, becomes medically significant. Daily observation of the bowel movement, can warn us very often when intestinal tract diseases are in their infancy, and will be of great value to the physician seeking information concerning the intestinal tract and the rest of the body as well.