What is black-coloured stool called?

Melaena usually describes stool that is black, sticky or tar-like and may have a particularly strong smell. Blood can become dark as it is digested while moving through the stomach and small intestine. A dark stool can also follow iron tablets, bismuth-containing medicines, or strongly pigmented foods, so colour alone cannot identify the cause.

Possible digestive causes include inflammation of the stomach lining, Helicobacter pylori infection, or a peptic ulcer. These conditions do not explain every dark stool, and a clinician may need to assess the appearance and your other symptoms.

If the stool is genuinely black and tarry, contact a healthcare professional promptly, especially if you have not taken iron or a bismuth medicine. Note when it started, how many bowel movements looked different, and any abdominal discomfort. Bring a list of medicines, including pain relievers and supplements. Do not stop prescribed medicine without advice.

Seek emergency help for black stool with fainting, marked weakness, confusion, breathlessness, vomiting blood, severe abdominal pain, or a fast heartbeat. These symptoms can accompany significant blood loss. Even without them, repeated tarry stools should be assessed urgently rather than watched at home.

Ask whether the stool could be melaena, whether your medicines or supplements can darken it, and which tests may clarify the source. You can also ask whether symptoms suggest gastritis, Helicobacter pylori infection, or peptic ulcer disease.