[?] Subscribe To This Site

black diarrhea - what causes black diarrhea or melaena?

What causes black diarrhea ? I'm often asked asked this question. These dark, liquid stools, what doctors call melaena, are due to blood in stool from gastrointestinal bleeding. It is never a symptom of ibs or the irritable bowel syndrome as such. The blackness of the stool is due to the change in the type of iron that is contained within the bloody stool, as it passes from the upper gut to the lower gut. The stools are formed anywhere from the mouth to the large bowel, so whilst most doctors look for a cause in the stomach, it can occur further down.

When you visit your doctor they will take a history and try to work out where the bleeding is likely to be coming from. You will need blood tests and an endoscopy test usually (camera test to look into the esophagus, stomach and duodenum). Other tests may include a faecal occult blood test (looking for blood in the stool), special x-rays including CT and maybe a more extensive test called an enteroscopy that looks further into the small bowel. If no cause is found then a colonoscopy maybe needed to determine the cause of these bloody stools.If you have any questions or concerns about this, you might like to use the free online doctor advice service or virtual doctor for more information.

What causes melaena?

The black diarrhea is normally caused because of bleeding in the upper gut. There are lots of causes for this. It can be due to bleeding in the proximal colon (1st bit of your large bowel) or from the small bowel too. Causes include:

Pseudo (i.e Bleeding not from the gut) causes:

Epistaxis (nose bleeds)

Oral bleeding if excessive

Iron rich containing foods (but have to be in large quantities!)

Swallowing blood from the lung (haemoptysis)

Esophagus (oesophagus)

Esophagitis (oesophagitis)

Esophageal (oesophageal)Varices

Esophageal (oesophageal) Ulcer

Mallory-Weiss tear (cut in the lower esophagus/oesophagus caused caused by excessive retching)

Esophageal (oesophageal)angiodysplasia

Osler-weber-Rendu syndrome

Stomach

Gastric benign ulcer

Gastric cancer

Gastric varices

Gastritis (rarely)

Gastric angiodysplasia

Dieulafoy

Duodenum

Duodenal Ulcer

Duodenal cancer

Duodenal angiodysplasia

Crohns disease

Dieulafoy

Small bowel

Crohns disease

Malignancy/lymphoma

Meckel's diverticulum

Colon

Colon cancer (particularly if in the cecum or proximal colon)

Angiodysplasia

What does dark diarrhea stool indicate? It indicates blood in stool that needs further investigation usually with endoscopy. As previously mentioned, If you have any questions or concerns about this, you might like to use the free online doctor advice service or virtual doctor for more information.

Black diarrhoea?Ask Questions And Share your experience by leaving a comment for others

Ask questions about black diarrhoea here. Have you had a problem with black diarrhoea? Do you currently have a problem with black diarrhoea stool? Are you a doctor who deals with black diarrhoea? Are you a trainee doctor learning about this? Do you have comments to make on black diarrhoea? Share it with other sufferers here, its so easy to do and may help others!

Enter The Title For Your Comment Or Question Here

Write your question or comments here! [ ? ]

Upload A Picture (optional) [ ? ]

Add Picture Caption (optional)

Author Information (optional)

To receive credit as the author, enter your information below.

Your Name	(first or full name)
Your Location	(ex. City, State, Country)

Submit Your Contribution

Check box to agree to these submission guidelines.

(You can preview and edit on the next page)

What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

Painful black watery diarrhea
I recently started taking a new heartburn medicine(Prevacid) and since have had a really bad case of diarrhrea. I was taking Prilosec otc before and never ...

To return to the ibs-help-online homepage click here

footer for black diarrhea page