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What Causes Black Stool?
Posted on
Fri, 6 Oct 2017
Medically reviewed by
Ask A Doctor - 24x7 Medical Review Team
Fri, 6 Oct 2017
Answered on
Tue, 31 Oct 2017
Last reviewed on
Question : This morning I had a very dark almost black bowel movement
Brief Answer:
black tarry stool suggestive of upper g.i bleed.
Detailed Answer:
There are a few things to consider when a person says he has dark color in the stool.
The first thing is if it is really blood. There are some food that might be in stool and give the impression of black color .Unless it really black and tarrry like charcoal(which is clear that it is blood). Black tarry stool is often accompanied with blood in stool.When bleed is un upper part of gut blood is acted upon by acid which gives black color to stools. A stool for occult blood test or a stool microscopy that will confirm the presence of blood with the stools.
Generally, blood coming from higher levels (stomach and small bowel) converts into a dark coal black colour due to the changes the blood has in the bowel. It is the bleeding from lower parts (colon) that will show as bright red blood.
Have you ever had a colonoscopy done? After the age of 50, it is recommended that all people should have a colonoscopy every 5-10 years. Even if you have had this test in the last 5 years it might be recommended to repeat it as you are having this bleeding if the stool tests confirm you are really bleeding.
A CBC would be a good test to be done if you suspect bleeding to see if you are developing anaemia as a complication of bleeding and need treatment for it or not.
So to conclude:
1. we need to be sure you are bleeding or not- a stool test like faecal occult blood test and or stool microscopy for blood will help in this.
2. if it is confirmed that you are bleeding then you will need a colonoscopy to find the cause of it.
I hope this is helpful and answers your questions but please feel free to reply in case any more clarification is needed on this.
Kind regards,
black tarry stool suggestive of upper g.i bleed.
Detailed Answer:
There are a few things to consider when a person says he has dark color in the stool.
The first thing is if it is really blood. There are some food that might be in stool and give the impression of black color .Unless it really black and tarrry like charcoal(which is clear that it is blood). Black tarry stool is often accompanied with blood in stool.When bleed is un upper part of gut blood is acted upon by acid which gives black color to stools. A stool for occult blood test or a stool microscopy that will confirm the presence of blood with the stools.
Generally, blood coming from higher levels (stomach and small bowel) converts into a dark coal black colour due to the changes the blood has in the bowel. It is the bleeding from lower parts (colon) that will show as bright red blood.
Have you ever had a colonoscopy done? After the age of 50, it is recommended that all people should have a colonoscopy every 5-10 years. Even if you have had this test in the last 5 years it might be recommended to repeat it as you are having this bleeding if the stool tests confirm you are really bleeding.
A CBC would be a good test to be done if you suspect bleeding to see if you are developing anaemia as a complication of bleeding and need treatment for it or not.
So to conclude:
1. we need to be sure you are bleeding or not- a stool test like faecal occult blood test and or stool microscopy for blood will help in this.
2. if it is confirmed that you are bleeding then you will need a colonoscopy to find the cause of it.
I hope this is helpful and answers your questions but please feel free to reply in case any more clarification is needed on this.
Kind regards,
Above answer was peer-reviewed by :
Dr. Nagamani Ng
Answered by
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