What should you know about very black stool?

Bleeding from the stomach or the first part of the small intestine can be digested as it travels through the bowel, turning stool black and tar-like. Conditions such as Peptic Ulcer, Gastritis or Helicobacter Pylori Infection may be involved. Iron supplements, bismuth-containing medicines and very dark foods can also change stool colour without bleeding. Tarry texture, a strong unusual smell, repeated episodes or other symptoms make bleeding more concerning than colour alone.

Notice whether the stool is sticky or tarry, how often it has happened, and whether you have taken iron, bismuth or medicines that can irritate the stomach. Arrange prompt medical advice rather than waiting for several episodes if the colour is unexplained. Do not stop a prescribed medicine without advice. A clinician may ask about medicines, abdominal symptoms and bowel changes, then decide whether examination or testing is needed.

Seek emergency care for black tarry stool with fainting, severe weakness, confusion, rapid heartbeat, breathlessness, severe abdominal pain, vomiting blood or vomit resembling coffee grounds. Urgent assessment is also sensible when black stool keeps returning, follows a new stomach symptom, or occurs while taking blood-thinning medicine. Keep a list of medicines and note when the change began.

Could a medicine, supplement or food explain the colour? Does the texture suggest digested blood? Which symptoms would mean I should go straight to emergency care? Do I need tests for stomach irritation, an ulcer or Helicobacter Pylori Infection?