HWN Suggests

Dr. Narula Gastroenterology

Only blood that originates from a high source, i.e. small intestine, stomach, or esophagus, or bleeding from a lower source, i.e. proximal colon, that occurs slowly enough to allow for enzymatic breakdown is associated with melena. A rough estimate is that it takes about 14 hours for blood to be broken down within the intestinal lumen; therefore if transit time is less than 14 hours the patient will have bright red blood in their stool, and if greater than 14 hours the patient will exhibit melena. Causes of "false" melena include iron supplements, Pepto-Bismol, Maalox, lead, blood swallowed as a result of a nose bleed (epistaxis), and blood ingested as part of the diet, as with consumption…

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Articles of Interest

58-Year-Old Woman With Melena

Upper GI tract bleeding is defined as bleeding from a site proximal to the ligament of Trietz. However, it is important to acknowledge that in 90% of patients melena originates proximal to the ligament of Treitz, but in 10% it can originate from the distal small bowel or right side of the colon.

Causes of Melena and Effective Examination Strategies in Children

The upper gastrointestinal tract was the most common bleeding source of melena in children. As in adults, esophagogastroduodenoscopy is the primary endoscopic method of choice. Furthermore, small bowel capsule endoscopy may be useful in identifying the bleeding source in children without upper gastrointestinal lesions.

Melena as an unusual presentation of gastrointestinal stromal tumour, a case report

Gastrointestinal Stromal Tumors (GISTs) are a rare slow growing malignancy, accounting for less than 1% of all gastrointestinal (GI) tract tumors. These tumors are usually discovered incidentally by endoscopy, surgery or radiology. However on occasions they may present with significant symptoms including GI blood loss.

The Presence of Melena Predicts a Proximal Bleeding Site Among Patients With Obscure Gastrointestinal Bleeding...

Melena is a hallmark symptom of upper gastrointestinal bleeding and results from the digestion of blood lost proximal to the ligament of Treitz in the majority of cases. However, whether melena also predicts bleeding in the proximal small intestine (SI) in the setting of obscure gastrointestinal bleeding (OGIB) is unknown.

What Else Could Cause Black Stool?

Some foods that turn stool dark are black licorice, chocolate sandwich cookies, beets, and artificial black, blue, or red food coloring. This discoloration is usually harmless and will go away after the food is digested. Black stools could also be caused by iron supplements or bismuth subsalicylate (the active ingredient in Pepto-Bismol).

What’s the Difference Between Hematochezia and Melena?

Melena refers to black stools, while hematochezia refers to fresh, red blood in your stool. This blood might be mixed in with your stool or come out separately. Hematochezia usually comes from the colon, while melena usually comes from a higher point in your GI tract.

Woman With Melena and Nausea

Hemangiomas of the small intestine are a rare vascular malformation and usually present with gastrointestinal bleeding.1,2 A routine endoscopy could not detect the lesion, thus making it difficult to diagnose. In our case, bedside ultrasonography played a critical role in detecting the probable cause of intestinal bleeding. Combined with the patient’s symptoms, such as melena and nausea, the presumed lesion was suggestive of the upper small intestine, which provided clues to the ensuing exploratory laparotomy. After surgery, the patient’s blood pressure and hemoglobin levels improved and she was discharged with stable vital signs.

Resources

TeachMe Surgery

Melena usually occurs as a result of an upper gastrointestinal bleed, however can also occur from bleeding occurring in the small bowel (albeit rare) There are a number of causes for upper GI bleeding, however the most common are peptic ulcer disease, variceal bleeding, and malignancy.