A. Although it's a sensitive subject for some, observing your feces on a regular basis is a very good health habit. You can tell a lot of things about your general health and, as in your case, detect disease of the intestinal tract by what you see. A single incident of minimal bleeding may not be significant, but continued bleeding can be an indicator of a serious problem. Since blood in the stool is an indication of bleeding anywhere in the digestive tract, it's important to determine where it is coming from.

If the blood is black or "tarry," called melena, the bleeding is likely confined to the upper digestive tract, particularly the stomach or small intestine, but it can be from as high up as the esophagus. Ulcers or irritation of the wall typically cause upper digestive tract bleeding, but cancer also may be a cause.

If the blood is bright red, called hematochezia, the bleeding is likely to be in the large intestine or rectal area. If the blood is only streaked on the outside of the feces, the origin is even more likely to be from a hemorrhoid or crack in the skin of the anus. However, one can see bright red blood from as far up as the esophagus if the bleeding rate is high enough.