MELENAMELENA

207-311-155207-311-155

DefinisiDefinisi In In medicinemedicine, , melenamelena or or melaenamelaena

refers to the black, "tarry" refers to the black, "tarry" fecesfeces that that are associated with gastrointestinal are associated with gastrointestinal hemorrhagehemorrhage. The black color is . The black color is caused by oxidation of the caused by oxidation of the ironiron in in hemoglobinhemoglobin during its passage during its passage through the through the ileumileum and and coloncolon..

CausesCauses The most common cause of melena is The most common cause of melena is peptic ulcerpeptic ulcer

disease. Any other cause of bleeding from the disease. Any other cause of bleeding from the upper gastro-intestinal tract, or even the upper gastro-intestinal tract, or even the ascending colon, can also cause melena. Melena ascending colon, can also cause melena. Melena may also be a sign of drug overdose if a patient is may also be a sign of drug overdose if a patient is take anti-coagulants, such as warfarin.take anti-coagulants, such as warfarin.

Melena is usually not a Melena is usually not a medical emergencymedical emergency because the bleeding is slow. Urgent care however because the bleeding is slow. Urgent care however is required.is required.

A less serious, self-limiting case of melena can A less serious, self-limiting case of melena can occur in newborns two to three days after delivery, occur in newborns two to three days after delivery, due to swallowed maternal blood.due to swallowed maternal blood.

Melena vs. hematochezia Melena vs. hematochezia Bleeding originating from the lower GI tract (such as the Bleeding originating from the lower GI tract (such as the

sigmoid colonsigmoid colon and and rectumrectum) is generally associated with the ) is generally associated with the passage of bright red blood, or passage of bright red blood, or hematocheziahematochezia, particularly when , particularly when brisk. Blood acts as a brisk. Blood acts as a catharticcathartic agent in the intestine, agent in the intestine, promoting its prompt passage. Only blood that originates from promoting its prompt passage. Only blood that originates from a high source (such as the a high source (such as the small intestinesmall intestine), or bleeding from a ), or bleeding from a lower source that occurs slowly enough to allow for oxidation, is lower source that occurs slowly enough to allow for oxidation, is associated with melena. For this reason, melena is often associated with melena. For this reason, melena is often associated with associated with hemorrhagehemorrhage in the in the stomachstomach or duodenum or duodenum (upper gastrointestinal tract), for example by a peptic ulcer. A (upper gastrointestinal tract), for example by a peptic ulcer. A rough estimate is that it takes about 14 hours for blood to be rough estimate is that it takes about 14 hours for blood to be broken down within the intestinal lumen; therefore if transit broken down within the intestinal lumen; therefore if transit time is less than 14 hours the patient will have hematochezia time is less than 14 hours the patient will have hematochezia and if greater than 14 hours the patient will exhibit melena. and if greater than 14 hours the patient will exhibit melena. One often-stated rule of thumb is that melena only occurs if the One often-stated rule of thumb is that melena only occurs if the source of bleeding is above the ligament of Treitz.source of bleeding is above the ligament of Treitz.

[edit] Diagnosis[edit] Diagnosis