What should you know about black stool and bleeding?

Bleeding above the small bowel can be changed by digestion, producing stool that is black, sticky, and tar-like rather than bright red. A peptic ulcer, gastritis, or irritation linked with Helicobacter pylori infection may present with this type of bleeding. Not every dark stool is blood: iron medicines and strongly coloured foods can alter stool colour. The difference is not always clear at home, especially when the stool has a tarry texture or a new unpleasant odour. A symptom does not identify one condition by itself.

Contact a medical service promptly about new black stool, even if you have no pain. Note when it began, how often it occurred, whether it was sticky, and any vomiting or light-headedness. Bring or share a list of medicines, including pain relievers and supplements. Avoid self-treating with anti-inflammatory pain medicines while waiting for advice. A clinician may decide whether examination, blood testing, or digestive-tract assessment is appropriate.

Seek emergency help for black stool with faintness, marked weakness, rapid breathing, confusion, cold sweats, severe abdominal pain, or vomiting blood or material that looks like coffee grounds. These signs can accompany blood loss. If the stool is dark after a known medicine or food and returns to its usual colour, still ask a clinician for advice if the cause is uncertain or the change recurs.

Ask whether the colour could be from a medicine or food, whether bleeding needs investigation, what medicines to pause or continue, and how to recognise worsening blood loss. Ask whether peptic ulcer disease, gastritis, or Helicobacter pylori infection could be relevant.