ONE OF the most distressing, if not the most common, symptoms of gastrointestinal disease is bleeding. Hemorrhage is manifest in two ways: by hematemesis, the vomiting or regurgitation of gross blood, or by melena, which is defined as the discharge from the bowel of black altered blood. The custom of discussing these two conditions together is based on their common genesis and their frequent symptomatic coexistence. In this discussion the broad use of the term melena will be used to include the discharge of black, red or occult blood from the anus.
At the outset, it should be recalled that hematemesis and melena are signs and not disease entities. Moreover, their pathogenesis may lie within or without the digestive tract. These symptoms are of special interest to the surgeon for two reasons: First, as pointed out by Jones, the implication in a given case or consideration is that the problem