Haematemesis is the vomiting of blood, either bright or altered blood (so-called ‘coffee grounds’ vomitus), due to the action of acid on the blood. Melaena is the passage of black tarry stools. The tarriness is characteristic and distinguishes melaena from the passage of black stools due to dietary agents, including the ingestion of iron. Haematemesis occurs from a point that is usually not distal to the duodenum but melaena may occur not only from a proximal bleeding site, but rarely from a small intestinal cause.
Melena strongly suggests, and hematemesis confirms, that bleeding is of upper gastrointestinal origin. In this situation, seek historical evidence for common causes such as peptic ulcer, cirrhosis with esophageal or gastric varices, gastritis, esophagitis, Mallory–Weiss tears, and malignancy.
In a patient has lost a lot of blood, transfusion will be recommended to bolster blood volume. Diagnostic tests can be run to find out why the patient is vomiting blood. With a diagnosis, a doctor can make treatment recommendations which will address the problem in the long term. These recommendations can include surgery, medications, and dietary recommendations. The patient may be kept in the hospital until she or he stops vomiting blood and appears stable.