https://www.ncbi.nlm.nih.gov/books/NBK411/
Hematemesis, Melena, and Hematochezia - Clinical Methods - NCBI Bookshelf
Hematemesis is the vomiting of blood, which may be obviously red or have an appearance similar to coffee grounds. Melena is the passage of black, tarry stools....
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https://www.mdanderson.org/cancerwise/what-is-hematemesis--vomiting-blood--explained.h00-159774867.html
What is hematemesis? Vomiting blood, explained | UT MD Anderson
What is hematemesis, and what should you know about this alarming symptom? Gastrointestinal medical oncologist Jaffer Ajani, M.D., explains.
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