MELENA (syn.: Tarry stool) - unformed black tarry stool with a fetid odor; a characteristic sign of esophageal, gastric or intestinal bleeding. It can also be observed in connection with ingestion of blood, for example, with nose or lung bleeding. Even moderate bleeding (50 - 100 ml) causes the black color of the stool, not manifesting itself as any pronounced subjective disorders. With more heavy bleeding, melena manifests itself after 30 minutes - 2 hours and is accompanied by symptoms of acute blood loss.
The black tarry color of feces is due to the presence in it of sulphurous iron formed in the intestine as a result of the interaction of hemoglobin and hydrogen sulfide. After taking certain medications (activated charcoal, iron, bismuth), the stool can also become dark in color, but the stool is usually properly formed and does not have a lacquer shine. The main method for detecting melena is to examine the patient's bowel movements. If this is not possible, but there is anamnestic information about the tar-like character of feces during previous stool, as well as in the presence of other symptoms of internal bleeding (pallor of the skin, collapse, decreased hemoglobin in the blood, etc.), a rectal examination should be performed with an examination of the feces collected from the walls rectum. This study should also be carried out in sudden fainting conditions of unknown origin.
In newborns, true and false melena are distinguished. True melena may appear already in the first days after birth due to a violation of blood coagulation processes. At the same time, hemorrhages from the umbilical wound, hemorrhages in the skin and conjunctiva, bloody vomiting , etc. are observed. False melena can be caused by swallowing the mother’s blood during childbirth and in the process of breast sucking with cracked nipples, as well as own blood if the mucous membrane of the mouth and nose.
In older children, melena is one of the main, and often the only symptom of a bleeding Meckel diverticulum. Moreover, bleeding can be massive and lead to severe anemia .
If melena is detected, the patient should be urgently referred to a surgical hospital. Before hospitalization, he is forbidden to eat; only cold water is allowed to drink in small sips; it is advisable to put an ice bubble on your stomach. In the hospital, an emergency endoscopic examination (esophagogastroduodenoscopy, colonoscopy) is performed, which allows in most cases to establish the source of bleeding, as well as to carry out activities aimed at stopping it.