Posted 08 July 2014 - 11:25 AM
Just as a general question.
I was concerened about bleeding a while ago and i asked my GI about it. She informed me blood quickly turns to black tar very shourtly after being exposed to your degestive juice unless you have very bad D and it does have the time to turn black. My question is, when you have normal... well... normalish bms, how far up into your degestive track does bleeling have to occure for it be black? Does it depend? I know bright red and red are a sign of internal or external hemmies.
Let me know.
Posted 08 July 2014 - 11:56 AM
From the Merck Manual for Health Professionals
Melena is black, tarry stool and typically indicates upper GI bleeding, but bleeding from a source in the small bowel or right colon may also be the cause. About 100 to 200 mL of blood in the upper GI tract is required to cause melena, which may persist for several days after bleeding has ceased. Black stool that does not contain occult blood may result from ingestion of iron, bismuth, or various foods and should not be mistaken for melena.
Ph.D in Biology