Blood that comes from the stomach or higher up in the colon is dark or black by the time the puppy (or a person) goes to the bathroom.
Blood from lower in the colon and rectum is still red.
(People with bright red blood in their stools - are usually bleeding from hemorrhoids -- which are very low in the rectal area).
**** The longer blood is out of a vein or artery - the more coagulated (thickened) it becomes and the darker it becomes.
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If blood sits in the stomach for a while - it will become thickened and very dark (as you said, it could resemble coffee grounds). However, fresh new blood that has entered the stomach could still be red when thrown up.
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You can even see this with cuts on the outside of your body. If you have a cut on your arm, the bleeding will at first be very thin and very red.... but soon, it will begin to coagulate/thicken (this is what eventually stops the bleeding and even forms a scab) and as this occurs, it will become much darker in color. This same thickening and color change occurs inside our body. (The longer the blood is in our body - before we go to the bathroom or throw up - the darker and thicker it will become......and if it spends a long time in the colon moving along before we go to the bathroom - it certainly will be very dark and almost black. )
I feel like I rambled a little - but hope this helps.
Carol Jean |